Posted on 1 April 20261 April 2026 by Joe

Your Body Makes Its Own Cannabis — And Running Is the Key That Unlocks It

Your Body Makes Its Own Cannabis — And Running Is the Key That Unlocks It | The Certified

Plant Science · The Endocannabinoid System

Your Body Makes Its Own Cannabis — And Running Is the Key That Unlocks It

Scientists have been searching for decades for what causes the runner's high. The endorphin theory turned out to be mostly wrong. What the evidence now points to is something far more interesting — your body producing its own versions of the compounds found in cannabis, triggered by exercise.

The Grower's Connect · 2025 · 11 min read

14/17 Studies confirmed AEA rise after exercise

571 Human participants across 21 trials

70–85% Max heart rate sweet spot for release

Listen to this article Your Body Makes Its Own Cannabis — And Running Is the Key That Unlocks It

Five weeks into this series and we have moved from the plant outward. We examined what sucrose does inside the stem. We looked at how the brain responds to decades of heavy use. We watched scientists coax a naked cell back to life. We mapped the microscopic architecture of the flower itself. This week we turn to something that connects the plant to the person in a way most growers have never considered.

Your body has its own endocannabinoid system. It produces its own cannabinoid-like molecules. And a growing body of peer-reviewed evidence suggests that moderate-intensity endurance exercise — running, specifically — is one of the most reliable ways to trigger their release. This isn't fringe science or wellness marketing. It's a systematic review published in The Neuroscientist, covering 21 human clinical trials and 571 participants.

The implications run in two directions simultaneously. For the cannabis consumer, it tells you something important about what the plant is actually binding to — and why it works the way it does. For the grower, it reframes what you are cultivating. You are not producing a foreign substance that overrides the brain. You are producing plant-based versions of molecules the brain already knows, already produces, and already uses to regulate mood, pain, anxiety, and motivation.

First, the Endorphin Myth

Before we get into what the evidence actually shows, it's worth clearing the ground of what it doesn't show — because most people have been told the wrong story for decades.

The runner's high was first attributed to endorphins in the 1980s. The idea was straightforward: intense exercise releases endorphins, endorphins bind to opioid receptors, opioid receptors produce euphoria. It was widely reported, widely believed, and is still repeated today.

The problem is that endorphins are hydrophilic molecules — water-soluble. The blood-brain barrier is largely impermeable to water-soluble molecules. Peripheral endorphins physically cannot cross into the brain in meaningful quantities. The machinery needed to produce the runner's high is inside the brain. The endorphins produced in the body largely cannot reach it.

The evidence backed this up directly. When researchers blocked opioid receptors entirely using naltrexone — preventing anything from binding to those receptors — the runner's high happened anyway. Euphoria was still present. Anxiety was still reduced. The opioid system wasn't the mechanism. So what was?

"When researchers blocked the opioid system entirely, the runner's high happened anyway. Euphoria was still present. Anxiety was still reduced. The endorphin theory was wrong."

The Endocannabinoid System — Your Body's Built-In Cannabis

In the early 1990s, researchers made two discoveries that changed the picture completely. In 1992, a molecule was identified in the brain that bound to the same receptors as THC. It was named anandamide — from the Sanskrit word for bliss. In 1995, a second molecule was discovered: 2-arachidonoyl glycerol, known as 2-AG.

Both are endocannabinoids — cannabinoid-like molecules produced naturally inside the body. Both are lipophilic, meaning fat-soluble. And critically, fat-soluble molecules can cross the blood-brain barrier with ease. Unlike endorphins, endocannabinoids produced in the body can actually reach the brain.

From the plant THC & CBD

Plant-derived cannabinoids that bind to CB1 and CB2 receptors in the brain. THC produces psychoactive effects via CB1. CBD modulates the system more broadly. Both are fat-soluble and cross the blood-brain barrier.

From your body AEA & 2-AG

Endogenous cannabinoids produced by the brain itself. Anandamide binds primarily to CB1 — the same receptor as THC. 2-AG is a full agonist at both CB1 and CB2. Exercise triggers their release into circulation.

The endocannabinoid system they activate regulates synaptic transmission, mood, reward, anxiety, appetite, memory, neuroprotection, and neuroinflammation. It also plays important roles in neural development. When a cannabis grower talks about what THC does in the brain, they are talking about what the brain's own endocannabinoid system does naturally. THC is a plant-based key to a lock the body built for itself. Anandamide is the body's own key to that same lock.

What the Review Found — 21 Studies, 571 People

The systematic review published in The Neuroscientist screened 278 records and included 21 human clinical trials meeting strict criteria: aerobic exercise, minimum 20 minutes, endocannabinoid blood levels measured before and after, published in peer-reviewed journals. The 571 participants included healthy adults, athletes, people with PTSD, major depression, chronic pain, and substance use disorder.

The Headline Numbers

14 of 17 studies found a significant increase in anandamide after acute exercise — an 82% replication rate
Only about half the studies found an increase in 2-AG, likely due to small sample sizes and greater biological variability
76% of studies found increases in OEA, another endocannabinoid-like molecule, after exercise
All 4 long-term exercise studies found endocannabinoid levels decreased after programs of 12 weeks or more
Opioid blockade with naltrexone did not inhibit endocannabinoid release, euphoria, or anxiety reduction after running

For a field studying a molecule that degrades quickly and is difficult to measure, an 82% replication rate across independent research groups, different participant populations, and different countries is notable.

Intensity Is Everything — The 70 to 85% Window

One of the most practically useful findings in the review is that endocannabinoid release is not simply triggered by moving your body. It is triggered by moving your body at the right intensity.

A pivotal study tested the same participants on four separate days at four different intensities: walking at under 50% of maximum heart rate, and running at roughly 70%, 80%, and 90% of maximum heart rate. The result was clean: only the two middle intensities — approximately 70% and 80% of maximum heart rate — produced a significant increase in anandamide. Walking produced nothing. High-intensity running at 90% produced nothing.

The Sweet Spot

The review's recommendation, drawn from accumulated evidence, is 70% to 85% of age-adjusted maximum heart rate for at least 30 minutes. In practical terms this is a pace where you can speak but feel genuinely challenged — sustainable for 30 to 45 minutes, but not a stroll. Duration should be at least 20 minutes. Peak mood benefits appear around 30 to 35 minutes. Endocannabinoid levels in the blood peak immediately after exercise and can be detected for up to 15 minutes post-exercise.

What the Endocannabinoids Are Actually Doing

The runner's high has four classically described components: euphoria, reduced anxiety, reduced pain sensitivity, and sedation. Here is what the evidence shows for each in relation to endocannabinoids.

Euphoria

Strong evidence

Endocannabinoid levels were roughly twice as high after running as walking. Euphoria tracked the same pattern. Blocking opioid receptors with naltrexone did not reduce either the endocannabinoid release or the euphoria — ruling out endorphins as the mechanism.

Anxiety Reduction

Strong evidence

8 out of 10 studies found reduced anxiety after acute exercise. Higher endocannabinoid increases correlated with greater anxiety reductions. This held even in PTSD, major depression, and substance use disorder populations.

Pain Reduction

Mixed evidence

Results were inconsistent across studies. One study found significant hypoalgesia after 30 minutes of running. Another found no effect in chronic pain patients. Appears to depend heavily on intensity, timing, and participant health status.

Sedation

No evidence yet

None of the 21 studies measured or detected sedation effects after exercise. A mouse study suggests post-exercise sedation may be a non-specific fatigue response that does not require endocannabinoid signalling at all.

The Long-Term Paradox

Here is the finding that surprised the researchers most — and has the most significant implications for anyone thinking about regular exercise and the endocannabinoid system.

After acute exercise, endocannabinoids go up. But after long-term regular exercise programs lasting 12 weeks or more, all four studies that measured endocannabinoid levels found they went down. Not just back to baseline. Measurably below it.

The mechanism proposed is an upregulation of FAAH — fatty acid amide hydrolase — an enzyme that breaks down anandamide. In physically active people, FAAH activity in lymphocytes was found to be higher than in sedentary controls. The body, it appears, compensates for repeated endocannabinoid elevation by becoming more efficient at clearing it. The same homeostatic intelligence that governs tolerance to cannabis in regular users appears to operate in regular exercisers — not through receptor downregulation but through accelerated degradation of the molecule itself.

What this means practically is not yet clear. It may be neutral — the body adapting its baseline without losing the capacity for acute elevation during exercise. Or it may have implications for mood regulation in long-term athletes. The review flags this as a priority for future research.

"The same homeostatic system that governs cannabis tolerance in regular users appears to operate in regular exercisers — not through receptor changes, but through faster degradation of the molecule itself."

The Stress Connection

The review identifies a relationship between the endocannabinoid system and the stress response that goes beyond exercise-induced euphoria.

Cortisol — the primary stress hormone — and anandamide levels were found to correlate positively. When exercise drove cortisol up, anandamide went up with it. In another study, a social stress test also increased anandamide. The researchers frame this through allostasis — the body's system for maintaining stability through change. Exercise is itself a stressor. The endocannabinoid release it triggers may be part of the body's mechanism for modulating how that stress is experienced, buffering the physiological stress signal with a neurobiological one that promotes calm and positive affect.

A study of cosmonauts during spaceflight adds a striking data point. In cosmonauts experiencing low stress, endocannabinoids were elevated. In those experiencing high stress and motion sickness, endocannabinoid elevation was absent and cortisol surged. The endocannabinoid system appears to function, at least in part, as a stress buffer — one that can be depleted by excessive stress rather than activated by it.

This is directly relevant to understanding what cannabis does therapeutically. When patients report using cannabis for anxiety, stress, or mood regulation, they are not introducing a foreign chemical that overrides normal function. They are supplementing a system that exists specifically to perform those regulatory functions — one that can be overwhelmed, depleted, or dysregulated by the conditions of modern life.

What This Means for Growers and Consumers

The relevance of this research to cannabis cultivation runs deeper than it first appears.

For anyone who grows and also uses cannabis, understanding that THC and anandamide bind to the same receptor — that the plant molecule is essentially mimicking a molecule your body already produces — reframes the experience of using cannabis in a meaningful way. It is not an alien substance producing an artificial state. It is a plant-derived key fitting a lock your brain evolved for its own purposes.

For medical growers and producers, the endocannabinoid research strengthens the biological rationale for cannabis as medicine in ways that go beyond anecdote. The anxiety reduction, mood elevation, and pain modulation that cannabis produces are all functions of the endocannabinoid system — documented in drug-free exercise studies, across hundreds of participants, in peer-reviewed journals.

And for the series of conversations we have been having here on The Grower's Connect — about what the plant is at a cellular level, what its flowers are under a microscope, what happens in the brain over a lifetime of use — this piece adds something important. The plant and the person share a receptor. The endocannabinoid system is the bridge between them. And running, it turns out, is one of the oldest ways the body has of activating that bridge on its own.

The Grower's Connect — Plant Science Series

Week 01 → Feeding Your Plant From the Inside Out: Sucrose Stem Infusion and 30%+ Yield Increases
Week 02 → What Heavy Cannabis Use Actually Does to Your Brain — And What the Science Really Says
Week 03 → Scientists Just Grew Cannabis From a Single Cell — And It Changes Everything
Week 04 → What's Actually Inside Your Cannabis Flower — And Why Understanding It Could Change How You Grow
Week 05 → Your Body Makes Its Own Cannabis — And Running Is the Key That Unlocks It — You're reading it

Source Study: Siebers M, Biedermann SV, and Fuss J (2022) Do Endocannabinoids Cause the Runner's High? Evidence and Open Questions. The Neuroscientist. 2023;29(3):352–369. doi:10.1177/10738584211069981 — Institute of Forensic Psychiatry and Sex Research, University of Duisburg-Essen, Germany. Published 2022.

Posted on 25 March 202625 March 2026 by Joe

What’s Actually Inside Your Cannabis Flower

What's Actually Inside Your Cannabis Flower — And Why Understanding It Could Change How You Grow | The Certified

Plant Science · Florogenesis & Flower Architecture

What's Actually Inside Your Cannabis Flower — And Why Understanding It Could Change How You Grow

Israeli researchers put cannabis flowers under a scanning electron microscope and mapped exactly how they form, branch, and develop. What they found challenges some of the most widely held assumptions in cultivation — including whether your plant is ever truly vegetative.

The Grower's Connect · 2025 · 10 min read

7 Orders of branching in one inflorescence

2 Flowers at every single node

Day-neutral Flower initiation is not photoperiod-triggered

Listen to this article What's Actually Inside Your Cannabis Flower

Four weeks into this series and the direction has been consistent. We looked at sucrose pushing through a stem to drive yield. We looked at brain scans showing what decades of heavy use does to working memory. We looked at scientists stripping cells naked to unlock the genetics of the future. This week we slow down and look at something that every grower interacts with every single day — the flower itself.

Not the bud as a product. The flower as a biological structure. What it actually is. How it actually forms. And why understanding that might quietly change how you think about your grow.

A 2019 study published in Frontiers in Plant Science by researchers at the Volcani Centre in Israel used scanning electron microscopy and stereomicroscope imaging to map cannabis flower development in detail across three cultivars. What they found is genuinely illuminating — and in some cases, directly challenges assumptions that are deeply embedded in everyday cultivation practice.

Your Plant Is Never Truly Vegetative

Let's start with the finding that will bother some growers most: the idea of a clean vegetative phase — where your plant is just building structure and hasn't started thinking about flowers — is probably not accurate.

The researchers found that under long photoperiod conditions, the ones growers call vegetative, cannabis plants were already producing solitary flowers in the axils of every leaf node. Not just flower primordia visible only under a microscope. Actual flowers. Two of them, sitting in the base of every leaf petiole, one on each side, each subtended by a bract.

In two of the three cultivars studied, these solitary flowers reached full anthesis — complete maturity — under 18/6 light. The plant had not been flipped. It had not been told to flower. It flowered anyway.

What this means scientifically is that cannabis flower initiation appears to be age-dependent and driven by internal signals, not triggered by photoperiod. The plant doesn't wait for the light to change. It begins its reproductive programme on its own schedule, governed by developmental age and internal hormonal cues, not the timer on your ballast.

"When you flip to 12/12, you are not telling the plant to start flowering. You are telling it to dramatically change the architecture of its branching system — around a process it has already begun."

The implication is worth sitting with. When you flip to 12/12, you are not telling the plant to start flowering. You are telling it to dramatically change the architecture of its branching system — to compress and intensify the inflorescence structure it has already begun building. That is a fundamentally different mental model of what the flip does.

The Phytomer — The Repeating Unit You're Working With

To understand what the researchers found, you need one concept: the phytomer. It is the basic repeating building block of the cannabis plant, and every node on your plant is one.

Each phytomer consists of four elements — an internode (the section of stem between nodes), a large fan leaf, two bracts, and two solitary flowers sitting in the base of the leaf petiole. This structure repeats up the entire plant, from the lowest node to the highest. The same unit. Over and over. And critically, the same structure is present whether the plant is under long or short photoperiod.

The Four Elements of Every Phytomer

The internode — section of stem between nodes, elongated under long photoperiod, compressed under short
The fan leaf — large photosynthetic compound leaf, reducing in size and lobe number as flowering progresses
Two bracts — modified leaf structures at the leaf petiole base, subtending the flowers on each side
Two solitary flowers — one in the axil of each bract, present at every node under both long and short photoperiod

What changes when you flip to 12/12 is not the phytomer itself. What changes is the scale and compression of the phytomers. Under long photoperiod they are large and spread out, with full-sized fan leaves and extended internodes. Under short photoperiod they miniaturise and compress, leaves reduce dramatically, internodes shorten, and the entire structure densifies into what we recognise as an inflorescence.

When you look at a cola, you are not looking at one thing. You are looking at a compressed stack of phytomers, each containing two individual flowers, each developing on its own timeline, surrounded by its own bract, with its own trichome development happening at its own rate.

What a Cannabis Flower Actually Is

Here is where the microscope work gets interesting for anyone who has ever looked closely at a developing bud and wondered what exactly they were looking at.

Each individual female flower is a remarkably minimal structure. Under the scanning electron microscope, the researchers mapped its development in sequential stages. The flower consists of a carpel — the ovule-bearing structure — enclosed within a perigonal bract: a specialised leaf-like structure that wraps around and envelops the ovary. This perigonal bract is different from the larger subtending bract that sits at the leaf base. It is a second, inner bract that directly surrounds the flower itself.

During early flower development a perianth — an early-stage outer floral envelope — is also present. The researchers documented that it degenerates as the flower matures, losing its structure and becoming barely visible as a thin membrane. By the time the flower approaches maturity, what you are looking at is essentially just the carpel, wrapped in the perigonal bract, with two stigmas extending from the top.

The Detail That Matters Most

Glandular trichomes begin developing on the perigonal bract before the stigmas have fully elongated. The structures producing every cannabinoid and terpene you are cultivating for form and begin their production cycle early in flower development — while the flower is still forming around them. Trichomes are not a late-stage feature.

Those two stigmas — the paired white hairs that growers use as their primary visual indicator of flower development — elongate unevenly, extending from the perigonal bract as the flower matures. Papilla cells develop on the stigma surface, covering it from tip to base. But by this point, trichome development is already underway.

The Inflorescence — Why Dense Branching Is the Point

Under short photoperiod, cannabis develops what the researchers formally classify as a highly branched compound raceme. Understanding this classification explains the structural logic behind what you are trying to achieve with training, pruning, and canopy management.

A raceme is an inflorescence where the main axis continues to grow and produce lateral flowering structures along its length, rather than terminating. Compound means those lateral structures themselves branch and produce further inflorescences of higher order. In cannabis, the researchers documented up to seven visible orders of branching within a single inflorescence — seven levels of nested branchlets, each carrying its own phytomers, each carrying its own pairs of flowers.

The density of your inflorescence — the compactness of your bud — is directly related to how many of these branching orders develop and how much they compress. The more branching orders that develop, the more flowers per unit of stem length, the more bracts per unit of volume, and therefore the more trichome-bearing surface area per gram of inflorescence.

This is the structural basis for trichome density in high-quality cannabis. It is not simply genetics, though genetics sets the ceiling. It is the plant's branching programme executing under the right conditions, compressing as many bract surfaces as possible into as small a space as possible.

Three Cultivars, Three Completely Different Endings

One of the most illuminating findings in the study is what happened at the very tip of the inflorescence in each of the three cultivars — because each one behaved completely differently at the same anatomical location.

Cultivar NB140

High THC · Indica dominant

The apical meristem eventually terminated by differentiating a normal, fully formed female terminal flower — about 8 to 10 days after the first stigmas appeared. The standard expected endpoint.

Cultivar NB150

High THC · Sativa-Indica mixed

The apical meristem terminated by producing a hermaphrodite terminal flower — with both pistils and anthers present simultaneously. Visible under microscope. Likely triggered by stress or ethylene and gibberellin fluctuations.

Cultivar NB130

~7% THC / 7% CBD · Sativa dominant

The inflorescence meristem simply never terminated. Seven months after the flip to short photoperiod, it was still producing new phytomers. An open, indeterminate structure with no programmed endpoint.

All three of these endpoints are governed by genetic programming in the meristem — by the molecular identity of that growing tip and its sensitivity to the hormonal signals that eventually tell it to stop. Different genetics, different outcomes at the same location in the plant. The same photoperiod, the same environment, three completely different developmental conclusions.

The Questions This Should Make You Ask

The value of this kind of research for growers is not in the technical detail itself. It is in the questions it generates. Here are the ones worth sitting with.

Questions from the Research

If your plant is already producing flowers under vegetative conditions, what does extending your vegetative period beyond a certain developmental age actually accomplish? At what point are you simply accumulating more phytomers rather than building a fundamentally different plant?
If trichome development begins before stigma elongation is complete, what does that mean for your interpretation of maturity indicators? Is the pistil colour change you use as a harvest signal actually lagging behind trichome development in a predictable way?
If the density of your inflorescence is determined by how many branching orders develop, what does your environmental management during the first two weeks of flower do to that branching programme? The stretch is not just about height — it is about the architectural decisions the plant is making.
If different cultivars terminate their apical meristems through completely different mechanisms, is the concept of a universal harvest window based on weeks of flower actually meaningful across different genetics? Or is each cultivar following its own internal clock to a structurally different endpoint?
If the phytomer is the same repeating unit at every node, what does defoliation at different stages actually remove in terms of that repeating architecture — and what is the downstream effect on the phytomers above?

These are not rhetorical questions. They are the kinds of questions that, once asked, tend to change how you observe your plants day to day. You start looking for the answers in the plant, not just in a feeding chart.

What This Connects to in Our Previous Work

There is a thread running through this entire series worth naming directly.

In week one, we saw that the cannabis plant's response to sucrose infusion was extraordinarily precise — 0.5 bar worked, 2 bar damaged. The mechanism was at the cellular and molecular level, but the outcome was visible in flower mass and cannabinoid yield. In week two, we saw that what cannabis does to the brain is specific to particular regions — not a general effect, but a targeted one in areas with high CB1 receptor density. In week three, we saw that protoplast viability at isolation determined everything downstream. The starting conditions set the ceiling.

"The plant is not a vague system responding to vague inputs. It is a precise biological machine executing a specific developmental programme, responding to specific signals, at specific times, in specific structures."

The common thread is precision. The more clearly you can see the plant's developmental programme — the architecture of the phytomer, the timing of trichome development relative to flower development, the branching programme that builds your inflorescence — the more accurately you can work with it rather than against it.

That is the argument for growers engaging with this kind of science. Not because you need to run scanning electron microscopes in your facility. But because the mental model you carry of what is happening inside your plant shapes every decision you make about light, environment, timing, and intervention. The more accurate that model, the better those decisions tend to be.

The Grower's Connect — Plant Science Series

Week 01 → Feeding Your Plant From the Inside Out: Sucrose Stem Infusion and 30%+ Yield Increases
Week 02 → What Heavy Cannabis Use Actually Does to Your Brain — And What the Science Really Says
Week 03 → Scientists Just Grew Cannabis From a Single Cell — And It Changes Everything About the Future of This Plant
Week 04 → What's Actually Inside Your Cannabis Flower — You're reading it

Source Study: Spitzer-Rimon B, Duchin S, Bernstein N and Kamenetsky R (2019) Architecture and Florogenesis in Female Cannabis sativa Plants. Front. Plant Sci. 10:350. doi: 10.3389/fpls.2019.00350 — Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel. Published April 2, 2019.

Posted on 18 March 202618 March 2026 by Joe

Scientists Just Grew Cannabis From a Single Cell — And It Changes Everything

Scientists Just Grew Cannabis From a Single Cell — And It Changes Everything About the Future of This Plant | The Certified

Plant Science · Cannabis Biotechnology

Scientists Just Grew Cannabis From a Single Cell — And It Changes Everything About the Future of This Plant

Czech researchers have achieved only the second-ever successful cultivation of cannabis protoplasts — naked plant cells stripped of their walls — and coaxed them into dividing. Here's why that quiet laboratory milestone could reshape how cannabis is bred, cloned, and engineered at a genetic level.

The Grower's Connect · June 2025 · 10 min read

2nd Ever achieved globally

83.2% Peak cell viability

9 Cannabis cultivars tested

Listen to this article Scientists Just Grew Cannabis From a Single Cell

Three weeks on The Grower's Connect, and a clear theme has emerged. We started by looking at how feeding sucrose directly into the stem at precisely the right pressure could push yields up by over 30%. Then we examined what heavy cannabis use does to the brain, and found the science far more nuanced than headlines suggest. This week, we go deeper still, into the cellular machinery of the plant itself. Because a quietly remarkable study just published in Frontiers in Plant Science has brought us one step closer to something that could fundamentally change cannabis cultivation as we know it.

The word "protoplast" won't mean much to most growers. By the end of this piece, it will, and you'll understand why it matters.

What Is a Protoplast, and Why Does It Matter?

A protoplast is simply a plant cell with its cell wall enzymatically removed. What's left is the naked cell, just the plasma membrane and everything inside it. That sounds destructive, but it's actually the opposite. Strip away the cell wall and something remarkable happens: the cell loses its identity. It forgets, in a sense, what it was programmed to be. It becomes capable of becoming anything.

Under the right conditions, a single protoplast can divide, redifferentiate, and regenerate into a complete, genetically identical plant. This process, called somatic embryogenesis or protoplast-to-plant regeneration, is the foundation of some of the most powerful tools in modern plant biotechnology, including genetic transformation and CRISPR-based genome editing.

The reason this matters for cannabis specifically is that the plant has been notoriously difficult to work with at the cellular level. Unlike tobacco, tomato, or Arabidopsis, the laboratory workhorse of plant biology, cannabis has resisted almost every attempt to regenerate a whole plant from isolated cells. That resistance has been a major bottleneck for cannabis research and breeding for decades.

"Strip away the cell wall and the cell loses its identity. It forgets what it was programmed to be — and becomes capable of becoming anything. That is the entire point."

What the Study Actually Did

Researchers at Palacký University Olomouc in the Czech Republic, led by Daniel Král, set out to crack that bottleneck. Published in June 2025 in Frontiers in Plant Science, the study reports only the second successful establishment and partial regeneration of cannabis protoplast cultures ever documented in scientific literature.

The team worked with nine cannabis cultivars, all industrial hemp varieties with varying CBD content, including USO 31, Finola, Fédora 17, Futura 75, and others. The work involved two distinct phases: first, optimising the conditions for protoplast isolation, and second, attempting to get those isolated cells to survive, divide, and form early-stage cell clusters called microcalli.

Getting the donor material right was everything. The researchers tested protoplast isolation from plants at multiple developmental stages, from one-week-old seedlings all the way through to six-month-old in vitro cultures and greenhouse-grown plants. The results were unambiguous: only leaves from one to two-week-old seedlings grown in sterile in vitro conditions produced protoplasts at a useful yield and viability. Older material consistently failed. Greenhouse-grown plants failed entirely.

Study Design at a Glance

9 industrial hemp cultivars tested, including both high and low CBD strains
Donor material tested from 1-week-old seedlings through to 6-month-old in vitro cultures and greenhouse plants
5 enzyme formulations evaluated for cell wall digestion
Gene expression tracked at 0, 24, 48 and 72 hours post-isolation across 6 target genes
Extended 14-day cultivation experiment confirmed microcallus formation and cell viability
Palacký University Olomouc, Czech Republic — published June 2025, Frontiers in Plant Science

The best results came from the USO 31 cultivar, producing yields of up to 9.9 million cells per gram of leaf tissue, with a peak viability of 83.2%, meaning more than four in five isolated cells were alive and functional immediately after extraction.

Key Finding

Just as we saw with sucrose stem infusion — where the difference between 0.5 bar and 2 bar of pressure determined whether yields increased by 34% or fell below the control — the protoplast work shows that precise conditions at the starting point determine everything that follows. You cannot compensate downstream for poor decisions upstream.

The Isolation Process — How You Strip a Cell Wall

The enzymatic solution used to digest away the cell wall is one of the most critical variables in the entire process. The team tested five different enzyme formulations, ultimately finding that a solution containing cellulase and macerozyme in a mannitol buffer — originally developed by Matchett-Oates et al. in 2021 — performed best.

The digestion ran for 16 hours in complete darkness at 25°C without shaking. Shorter digestion periods consistently failed. Adding a washing solution both before and after filtration was critical; skipping this step caused the protoplasts to clump and aggregate, making separation impossible. Centrifugation at 1000 rpm for 10 minutes, using a sucrose density gradient, provided the cleanest separation of viable cells from cellular debris.

One important finding: adding pectolyase, an enzyme used successfully in other species and suggested by several previous cannabis studies, actually made things worse at higher concentrations, likely by causing excessive enzymatic activity that damaged the cells before they could be collected.

Getting Them to Divide — The Hard Part

Isolating protoplasts is one thing. Getting them to survive in a culture and divide is another challenge entirely. The vast majority of cannabis protoplast research has stopped at isolation. Getting cells to actually re-enter the cell cycle, to start dividing, is where the field has repeatedly hit a wall.

This study used a regeneration medium originally developed for Arabidopsis thaliana, modified slightly for cannabis, supplemented with two plant growth hormones: indole-3-acetic acid (a natural auxin) and benzylaminopurine (a cytokinin). These two hormones together are what push a dedifferentiated cell back toward division and development.

The results: cultures remained viable after three days of incubation, microscopy confirmed cells had undergone at least one division, and an extended 14-day cultivation experiment produced visible microcalli, small clusters of dividing cells, that retained viability under FDA staining. This is the proof-of-concept moment. The cells didn't just survive. They started rebuilding.

What the Gene Expression Data Revealed

This is where the study goes beyond what any grower would attempt in their facility, but it's also where the most interesting science lives.

The researchers tracked gene expression in the cultured protoplasts at 0, 24, 48, and 72 hours using RT-qPCR, a technique that quantifies how actively specific genes are being transcribed. They monitored six genes across three categories: cell proliferation, abiotic stress, and oxidative stress.

Cell Proliferation Markers

PCNA, a protein directly involved in DNA replication and used as a standard marker of cell division, was undetectable in normal leaf tissue but increased significantly after protoplast isolation, peaking at 72 hours with a threefold increase in high-viability cultures. The auxin-responsive gene IAA-2 also showed a significant increase during cultivation, peaking at 48 hours with a 3.5-fold increase, indicating that the cells were actively responding to the growth hormones in the medium.

Abiotic Stress Markers

Two genes associated with the plant stress hormone abscisic acid, PP2C-1 and LEA34, both dropped significantly after isolation and stayed low throughout cultivation. This is good news: it means the cells were not experiencing escalating abiotic stress during the culture period. They adapted to their new environment quickly rather than deteriorating under it.

Oxidative Stress — The Critical Battle

When cell walls are enzymatically digested, reactive oxygen species, essentially cellular rust, accumulate rapidly. If not neutralised, these damage the plasma membrane and kill the cell. Two antioxidant genes, APX and CAT, showed complementary activation patterns throughout cultivation, indicating the cells' own antioxidant systems were engaged and functioning. In high-viability cultures, APX expression increased 3.5-fold within 24 hours. This coordinated antioxidant response, the researchers argue, was a critical factor in enabling the cells to survive and eventually divide.

"The cells didn't just survive the isolation process. They mounted an antioxidant defence, responded to growth hormones, and started dividing. That coordinated response is the entire story."

Why Viability at Isolation Predicts Everything That Follows

One of the most practically useful findings in the study is the relationship between viability at the point of isolation and everything that happens afterwards.

High-viability cultures, those above 60% viability at isolation, showed roughly twice the PCNA expression of low-viability cultures, stronger antioxidant responses, and more robust cell division overall. Low-viability cultures, below 15%, showed reduced expression across all proliferation and stress markers, consistent with impaired capacity to divide and survive.

The implication is clear: the quality of your starting material and your isolation technique determine your ceiling. You cannot compensate downstream for poor isolation conditions upstream. In the context of cannabis biotechnology, this means the painstaking work of optimising donor plant age, cultivation conditions, enzymatic solutions, and washing protocols is not procedural box-ticking; it is the entire game.

Why This Matters for Growers — Now and in the Future

Most growers will never set foot in a protoplast laboratory. So why should any of this matter to someone running a cultivation facility, a breeding programme, or a craft grow? Because this is how the next generation of cannabis genetics gets made.

The ability to work with cannabis at the single-cell level unlocks capabilities that are simply not possible through conventional breeding. Consider what becomes possible once protoplast-to-plant regeneration is fully achieved in cannabis:

Precision Genetic Transformation

Rather than working with whole plants and hoping a genetic modification takes hold uniformly, you can transform a single cell and regenerate an entire plant from it, guaranteeing that every cell carries the intended modification. This is non-chimeric transformation — the gold standard in plant genetic engineering.

CRISPR Genome Editing

Several research groups have already demonstrated transient CRISPR delivery into cannabis protoplasts, with transformation efficiencies reaching 75% in some studies. Once stable whole-plant regeneration is achieved, targeted editing of cannabinoid pathway genes becomes a realistic breeding tool.

Somatic Hybridisation

Protoplasts from two different plant species or varieties can be fused together, creating hybrid cells that combine the genetics of both parent plants. In cannabis, where specific terpene and cannabinoid profiles are of enormous commercial value, the implications are significant.

Ploidy Manipulation

Working at the cellular level allows controlled changes to chromosome number — a technique used in other crops to create larger, more vigorous varieties. In cannabis, this pathway to polyploid breeding has barely been explored.

You should know how I feel about all this. I am simply reporting what the study found. If this is overall good for us, I will let you decide for yourself. Just be mindful that we as people can always decide the direction of our own spaces, but not the overall market's direction. Similarly with food.

The Honest Limitations

Complete plant regeneration from cannabis protoplasts has not yet been achieved. The study reports microcallus formation — early-stage cell clusters — but not organised shoot or root development from those clusters. That next step remains the critical bottleneck, and the researchers are explicit that it is unresolved.

The work was done on industrial hemp varieties, all with low THC content. Whether high-THC varieties will respond similarly to the same isolation and culture conditions is unknown. Genotype variability is a significant factor throughout the study — results that worked well for USO 31 did not always transfer to Finola or other cultivars.

Where This Is All Going

Plant biotechnology in cannabis is accelerating. The first stable genetically modified cannabis plant was created just a few years ago using Agrobacterium-mediated transformation. CRISPR constructs validated in protoplasts are already being used to edit cannabis genes. And now, the second-ever report of cannabis protoplast cultivation and division has been published, with gene expression data that confirms the cells are genuinely viable, actively dividing, and mounting appropriate stress responses.

Each of these steps is incremental. None of them is the finish line. But they are building toward a moment when cannabis breeders will have access to the same precision genetic tools that have been available for maize, tomato, and rice for decades. When that moment arrives, everything as we know it will change.

The Grower's Connect — Plant Science Series

Week 01 → Feeding Your Plant From the Inside Out: Sucrose Stem Infusion and 30%+ Yield Increases
Week 02 → What Heavy Cannabis Use Actually Does to Your Brain — And What the Science Really Says
Week 03 → Scientists Just Grew Cannabis From a Single Cell — You're reading it

Source Study: Král D, Šenkyřík JB and Ondřej V (2025) Early protoplast culture and partial regeneration in Cannabis sativa: gene expression dynamics of proliferation and stress response. Front. Plant Sci. 16:1609413. doi: 10.3389/fpls.2025.1609413 — Department of Botany, Faculty of Science, Palacký University Olomouc, Czechia. Published June 6, 2025.

Posted on 11 March 202616 March 2026 by Joe

What Heavy Cannabis Use Actually Does to Your Brain

What Heavy Cannabis Use Actually Does to Your Brain — And What the Science Really Says | The Certified

Plant Science · Cannabis & The Brain

What Heavy Cannabis Use Actually Does to Your Brain — And What the Science Really Says

A major new study scanned over 1000 brains across 7 cognitive tasks. Only one showed significant lifetime impact. Here's what it means for growers, consumers, and anyone who wants to think clearly about this plant.

The Grower's Connect · March 2025 · 9 min read

1003 Adults brain-scanned

7 Cognitive tasks tested

1 of 7 Tasks with significant lifetime impact

Listen to this article What Heavy Cannabis Use Actually Does to Your Brain

Last week we looked at the science of feeding your plant from the inside out — how sucrose stem infusion at precisely 0.5 bar can push cannabis yields up by over 30%. This week we're flipping the lens. Instead of what cannabis produces, we're looking at what cannabis consumption does — specifically, what a rigorous new brain imaging study out of JAMA Network Open has to say about how heavy and recent cannabis use affects brain function.

This is research worth understanding properly. Not because it's cause for alarm — the nuance here is actually more reassuring than most headlines suggest — but because the details are genuinely useful whether you're a grower who also consumes, a medical patient, or someone who simply wants to make informed decisions about how and when they use.

Let's get into it.

The Study — What Was Actually Done

Published in January 2025 in JAMA Network Open, this research used data from the Human Connectome Project — one of the most comprehensive brain mapping datasets ever assembled. Researchers at the University of Colorado analysed 1003 young adults aged 22 to 36, putting them through 7 different brain function tasks inside an MRI scanner while measuring real-time brain activation.

The tasks covered working memory, reward processing, emotional recognition, language, motor function, logical reasoning, and theory of mind — essentially a full sweep of the cognitive functions we use daily.

Crucially, the researchers did something most cannabis studies don't: they separated recent use from lifetime use. Participants provided urine samples on the day of scanning to determine whether THC was still active in their system, allowing the team to distinguish between the short-term effects of being recently high versus the longer-term effects of years of heavy use.

How Participants Were Grouped

Heavy lifetime users — more than 1000 lifetime uses (88 participants, 8.8%)
Moderate users — 10 to 999 lifetime uses (179 participants, 17.8%)
Non-users — fewer than 10 lifetime uses (736 participants, 73.4%)
Recent users — THC detected in urine on scan day (106 participants)
All models adjusted for age, sex, income, education, alcohol and nicotine use

What the Scans Actually Showed

Here is where the story gets more interesting — and more nuanced — than most headlines will tell you.

Out of 7 cognitive tasks, only one — working memory — showed a statistically significant association with heavy lifetime cannabis use. Heavy lifetime users showed lower brain activation during the working memory task, with a small to medium effect size. The brain regions most affected were the anterior insula, the dorsomedial prefrontal cortex, and the dorsolateral prefrontal cortex — all areas known to have a high density of CB1 receptors, the primary binding site for THC.

Emotion, language, motor function, logical reasoning, reward processing, and theory of mind all showed no statistically significant association with lifetime heavy use once properly adjusted for demographics, alcohol use, and nicotine use. That is a meaningful finding. Six out of seven tasks showed no significant long-term impact.

"Six out of seven cognitive tasks showed no statistically significant association with heavy lifetime cannabis use. The science is more nuanced than the headlines suggest."

Recent Use Is a Different Story

Where the data gets more pointed is around recent use — people who had THC actively in their system on the day of scanning.

Recent cannabis users showed lower brain activation during both the working memory and motor tasks, and also showed poorer behavioural performance on the working memory task, episodic verbal memory, and theory of mind. Being recently high measurably affected how well people performed on cognitive tests — this is the clearest and most practical finding in the study.

However, even here the picture is more nuanced. After adjusting for race and education — both independently associated with a positive THC test — the theory of mind association disappeared entirely. And after applying false discovery rate correction across all 7 tasks, the working memory association was the only one that survived statistically.

Practical Takeaway

The impairment from recent use is real and measurable, but temporary. Studies suggest residual cognitive effects may persist for 2 to 4 weeks in regular users. If you need to perform well cognitively — a complex task, important decision-making, a demanding work situation — abstaining beforehand makes empirical sense.

What This Means for You

If You Grow

Managing a cultivation environment — VPD, nutrient schedules, plant health, environmental controls — is a working memory intensive activity. The study is a practical reminder that separating consumption from the cognitive demands of running a grow has real basis in the science.

If You Consume

For moderate users the findings are genuinely reassuring — no significant cognitive differences were found compared to non-users across any task. For heavy, long-term users the working memory finding is worth taking seriously as useful information, not cause for alarm.

For medical patients, the picture is more complex. This study focused on recreational community users, not patients managing specific conditions. The therapeutic benefits of cannabis for pain, anxiety, epilepsy, and other conditions may well outweigh cognitive trade-offs — that is a conversation for a medical professional, not a conclusion to draw from a single study.

On potency — THC content in cannabis products has increased significantly over the past two decades, and higher potency means more THC binding to those CB1 receptors. The study didn't measure dose or potency, but it's a reasonable inference that frequency and potency together are more impactful than frequency alone. As growers producing increasingly potent product, that context matters.

The Honest Limitations

The researchers are admirably upfront about what the study can't tell us. It is cross-sectional — a snapshot, not a long-term follow-up. We cannot say cannabis caused these brain differences. People who become heavy users may differ in other ways the study couldn't fully account for.

The sample was young adults aged 22 to 36, so findings may not apply to older adults — and more critically, not to adolescents, for whom the developing brain presents an entirely different risk profile. The study also lacked data on typical THC dose, potency, CBD content, or route of administration. A joint, an edible, and a high-potency concentrate deliver THC very differently, and the study treats all of these the same.

The Bigger Picture

Two weeks of research coverage on The Grower's Connect, and a theme is emerging: the cannabis plant rewards those who understand it deeply.

Last week that meant understanding how sucrose functions as a signalling molecule, and what precise delivery pressure does to yield outcomes. This week it means understanding what THC does in the CB1-receptor-rich regions of the prefrontal cortex, and why that matters specifically for working memory.

The takeaway from this study is not that cannabis is dangerous. It is that heavy, long-term use appears to have a specific and measurable effect on one important cognitive function, that recent use has broader but temporary effects, and that moderate use showed no significant difference from non-use. That is useful information. Use it.

"Growers and consumers who engage with the science honestly — including the parts that aren't entirely flattering — build more credibility and make better decisions than those who don't."

Source Study: Gowin JL, Ellingson JM, Karoly HC, Manza P, Ross JM, Sloan ME, Tanabe JL, Volkow ND. Brain Function Outcomes of Recent and Lifetime Cannabis Use. JAMA Network Open. 2025;8(1):e2457069. doi:10.1001/jamanetworkopen.2024.57069. University of Colorado Anschutz Medical Campus. Published January 28, 2025.

Posted on 4 March 20264 March 2026 by Joe

Feeding Your Plant From the Inside Out: What Sucrose Stem Infusion Could Mean for Your Yields

Feeding Your Plant From the Inside Out: What Sucrose Stem Infusion Could Mean for Your Yields | The Certified

Plant Science · Yield Optimisation

Feeding Your Plant From the Inside Out: What Sucrose Stem Infusion Could Mean for Your Yields

New peer-reviewed research out of the University of Ljubljana has shown that injecting a sucrose solution directly into cannabis stems during flowering can significantly boost flower mass and cannabinoid output — without disrupting photosynthesis.

The Grower's Connect · March 2025 · 8 min read

31% Increase in flower dry mass

34% Increase in cannabinoid yield

0.5 bar Optimal infusion pressure

As a grower, you've probably heard every pitch for squeezing more out of your plants — from specialist bloom boosters to light spectrum tweaks to microbial inoculants. Most of them promise a lot and deliver a little. So when a peer-reviewed study lands showing yield improvements of 31% in flower dry mass and 34% in cannabinoid output, it's worth sitting with it for a minute.

The technique is called Plant Stem Infusion of Sucrose — PSIS for short. It's been studied in maize, barley, soybean and sweet potato for decades, but this is the first time researchers have applied it directly to cannabis. The results, published in Industrial Crops & Products (2025), are genuinely interesting — not because PSIS is going to replace your current nutrient program, but because it opens up a real conversation about how we deliver energy to flowering plants.

Let's break it all down.

What Is Plant Stem Infusion, and Where Did It Come From?

The concept is simple: rather than feeding your plant through its roots or leaves, you inject a solution directly into the stem — bypassing surface uptake entirely and delivering nutrients straight into the plant's vascular system. Think of it like an IV drip for your plant.

The method has its roots in tree care. Arborists have been injecting fungicides, insecticides and minerals into trees for decades to treat everything from Dutch elm disease to emerald ash borer infestations. The logic is solid — if the roots or bark are compromised, go around them. The same principle has since been applied to crops, with boron and calcium injections in soybeans shown to improve pod development and overall yield as far back as 1987.

Sucrose specifically became the focus of PSIS research because of what sugar does for a plant beyond just being fuel. It acts as a signalling molecule, influencing gene expression, secondary metabolism, and cellular differentiation. When you introduce exogenous sucrose at the right moment and concentration, you're not just giving the plant more energy — you're potentially pushing it toward more productive metabolic pathways.

"Sucrose doesn't just feed the plant — it talks to it. At the right concentration, it can upregulate the same pathways responsible for producing secondary metabolites like cannabinoids."

How the Study Was Set Up

The research team at the University of Ljubljana grew 72 plants of a single CBD-dominant variety — Charlotte's Angel® (chemotype III: high CBD, low THC) — in a controlled indoor environment. Two variables were tested: the concentration of the sucrose solution (0%, 7.5%, 15%, and 30%) and the pressure at which it was delivered (0.5 bar, 1 bar, and 2 bar).

Starting on day 70 of the grow (two days into flowering), a standard 20-gauge hypodermic needle was inserted diagonally into the lowest node of each test plant, connected via IV tubing to a pressurised PVC tube filled with the sucrose solution. The system stayed live for the remainder of the grow — right through to harvest on day 133. Nine plants served as a negative control group with no infusion at all.

Measurements taken included plant height, stem and organ dry mass, chlorophyll content, net carbon assimilation, stomatal conductance, respiration, and cannabinoid yield via HPLC analysis of the top inflorescence of each plant.

Study Design at a Glance

72 plants total, single CBD-dominant variety (Charlotte's Angel®)
Infusion began day 70 — two days after flip to 12/12
Three pressure levels: 0.5 bar, 1 bar, 2 bar
Four sucrose concentrations: 0%, 7.5%, 15%, 30% (w/v)
System ran continuously through harvest at day 133
Cannabinoid analysis via HPLC — 16 cannabinoids profiled

What the Numbers Actually Showed

The Pressure Variable Was Everything

Here's the single most important takeaway: pressure matters more than concentration. Plants infused at 0.5 bar were the clear winners across almost every metric. They grew taller, produced significantly more flower dry mass, heavier stems, and delivered the highest cannabinoid yields. Everything above that — 1 bar and 2 bar — started working against the plant.

At 2 bar, cannabinoid yield actually dropped below the control group at certain sucrose concentrations. The plants were being overwhelmed. Think about it from a physiological standpoint: too much pressure forces too much solution into the vascular system too quickly. Instead of a gentle boost, you're creating mechanical and osmotic stress. The plant has to work to deal with it rather than benefit from it.

Flower Mass and Cannabinoid Yield

At 0.5 bar combined with 15% or 30% sucrose concentration, flower dry mass increased by up to 31% and total cannabinoid yield per plant jumped by up to 34% compared to the control group — both statistically significant results. These aren't marginal improvements. On a commercial scale, a 34% increase in cannabinoid yield per plant, without any change to genetics, lighting, or nutrient program, is a considerable number.

The dominant cannabinoid in the study was CBDA, which ranged from 10.72% to 12.42% across all groups, with no statistically significant difference between treatments in terms of cannabinoid profile — meaning the ratio of compounds didn't shift, just the total output. The plant was producing more of the same thing, not a different thing.

What About Leaf Mass?

Interestingly, all treated groups showed a reduction in leaf biomass compared to the control — though the difference wasn't statistically significant. This tracks with findings from other PSIS research: when you introduce exogenous sucrose, the plant reduces its reliance on photosynthesis. The leaves are doing less of the heavy lifting. This could partly explain why flower and stem mass went up while leaf mass edged down — the plant was redirecting energy rather than generating more of it.

Physiology: Mostly Business as Usual

One of the more reassuring findings is what didn't change. Net carbon assimilation, stomatal conductance, chlorophyll content, and photosynthetic efficiency all showed no statistically significant differences between treated and control plants. The infusion wasn't breaking anything in the plant's normal operating system.

The one exception: plants infused at 1 bar showed a significant increase in respiration on the first measurement day. More sucrose being pushed in means more metabolic activity — the plant was burning more energy to process the extra input. This wasn't observed at 0.5 bar, which again points to that gentler pressure being the sweet spot.

Key Finding

At 0.5 bar — the lowest pressure tested — plants received less total solution volume than higher-pressure groups, but showed the greatest yield improvements. More is not always more. The delivery rate matters as much as the dose.

Why Sucrose? The Plant Science Behind the Method

Sucrose is the primary sugar that plants move around internally. When your leaves photosynthesise, they produce sucrose and ship it through the phloem to wherever the plant needs energy most — growing shoot tips, developing fruits, building roots. During flowering, the demand from inflorescences is enormous.

By supplying sucrose exogenously via the stem, the researchers were essentially supplementing that internal supply chain at a critical moment. But sucrose does more than carry energy. It's been shown to trigger the accumulation of secondary metabolites — flavonoids, phenolic acids, anthocyanins — in various plant species. In cannabis, the same logic applies to cannabinoids, which are secondary metabolites produced under specific stress and signalling conditions. More sucrose, delivered at the right time, appears to nudge the plant toward ramping up cannabinoid biosynthesis alongside the increased biomass production.

The researchers note that sucrose also influences the activity of SnRK1 — a protein kinase involved in carbohydrate metabolism and starch production. Higher sucrose availability can upregulate the pathways responsible for biomass accumulation and overall yield.

The Honest Limitations — What This Study Doesn't Tell Us

This is a pilot study. The researchers are upfront about that. It used a single variety, a single genotype, in a single controlled environment. Before PSIS becomes something any commercial grower should seriously consider rolling out, a few questions need answers:

Does it work across chemotypes? Charlotte's Angel is a chemotype III — high CBD, low THC. High-THC varieties may respond differently. The research team specifically flags this as a priority for future work.

What's the optimal sucrose concentration? The study found that concentration alone didn't produce statistically significant differences across the groups — the benefit came from the combination of low pressure and higher concentration. There's likely a more refined sweet spot that further research could identify.

How does it scale? 72 plants in a 12m² controlled chamber is a tightly managed experiment. Adapting the injection system for a large commercial canopy — with consistent needle placement, sealed injection sites, and sterile media — is a real engineering and labour challenge. The researchers acknowledge this openly.

Contamination risk. A sucrose-rich environment inside plant tissue is a potential invitation for fungal pathogens. Sterile needles and sterilised solution would be non-negotiable in any practical application.

What This Could Mean for Growers Going Forward

Let's be real — most home growers and small-scale craft operators aren't about to start injecting their plants with IV drips this season. But that's not the point. The value of research like this is in what it tells us about how cannabis plants work, and what possibilities exist on the horizon for cultivation technology.

For commercial operations with high-value crops, even the research question here is worth watching. Cannabis is, as the study points out, one of the most valuable crops per gram of inflorescence biomass on the planet. A 30%+ yield improvement, if it translates reliably across varieties and environments, changes the economics of a grow room in a serious way. The additional cost of the infusion system, sterile supplies, and labour could absolutely be justified at commercial scale if the yield data holds up.

For the rest of us, the broader principle is useful: the timing and mechanism of nutrient delivery matters. The plant doesn't just care what you're giving it — it cares how, when, and at what rate it arrives. This study is another reminder that innovation in cannabis cultivation doesn't always come from a new bottle on the shelf. Sometimes it comes from asking fundamentally different questions about how plants work.

"Cannabis is one of the most valuable crops per gram of inflorescence biomass. Even a modest, consistent yield improvement justifies a serious look at this technology."

The Bottom Line

PSIS isn't ready for your grow room yet. But this research lays a genuinely solid foundation. The methodology is rigorous, the results are statistically significant where they count, and the researchers are appropriately careful about what the data does and doesn't say.

The key findings are clear: low pressure (0.5 bar) with a high sucrose concentration (15–30%) delivers meaningful improvements in flower dry mass and cannabinoid yield. High pressure works against the plant. The photosynthetic system remains largely intact. And the mechanism — sucrose as both energy source and signalling molecule — is well-supported by plant science literature across multiple species.

As the legal cannabis market matures and competition increases, growers who stay close to the science are the ones who will find the edges that matter. This is one worth keeping an eye on.

Source Study: Zupančič, K., Zupančič, L., Bitežnik, L., Malík, M., Lenarčič, D., & Flajšman, M. (2025). Enhancing yield of cannabis inflorescences and cannabinoids through plant stem infusion of sucrose: A novel cannabis cultivation approach. Industrial Crops & Products, 228, 120880. University of Ljubljana, Biotechnical Faculty, Department of Agronomy. Published March 2025.

Posted on 25 February 202625 February 2026 by Joe

Outdoor Cannabis in March: Preparing for the Flowering Stretch in South Africa

February is winding down, and if you are growing cannabis outdoors in South Africa, you can feel the change in the air. The intense summer heat is beginning to mellow, the mornings are slightly crisper, and the days are getting shorter. For the cultivator, this signals the most critical phase of the lifecycle: The Transition to Flower.

While the last few months have been about vegetative growth and enjoying the culture, March demands a shift in focus. It is time to get serious. To maximize your yield and ensure a mould-free harvest, you need to understand exactly what is happening inside your plants right now.

Recent scientific research has changed how we view this phase. According to a groundbreaking study on Cannabis sativa architecture, “flowering” isn’t just about buds appearing; it is a massive architectural renovation of the plant. Here is what you need to know to get your garden ready for the Autumn bloom.

The Science of the Shift: It’s Not Just About Light

Most growers assume that as soon as the light hits 12/12, the plant simply decides to flower. However, the study “Architecture and Florogenesis in Female Cannabis sativa Plants“ reveals that the process is far more complex. Understanding Florogenesis (flower formation) will help you stop guessing and start growing with precision.

1. The Myth of the “Pre-Flower”

Have you noticed small calyxes with white hairs (stigmas) at the nodes of your branches even though the days are still long? Many growers mistake this for the start of the flowering stage.

The research shows that these Solitary Flowers are actually day-neutral. This means their appearance is triggered by the age of the plant, not the sun. A mature plant will produce these solitary flowers regardless of the light cycle. Seeing them is a good sign—it means your plant is sexually mature—but it does not mean the true flowering stretch has begun.

2. The Compound Raceme: Flowering is Branching

The most significant finding for growers is that the short-day photoperiod (which we approach in March) triggers intense branching, not just bud formation.

When the plant detects the shortening days, it stops growing tall (monopodial growth) and transforms its shoot tips into what scientists call a Compound Raceme.

What is it? The plant begins producing compressed, miniature branches packed tightly together.
The Phytomer: The “bud” you see is actually made up of hundreds of basic units called phytomers (reduced sugar leaves, bracts, and flowers) stacked in a condensed spiral.

This means that during the March transition, your plant is frantically building a new, heavy internal structure.

Your March Grow Guide: 4 Steps to a Massive Harvest

Now that we understand that the plant is undergoing a structural overhaul, here is your checklist to support this architectural shift.

1. Inspect the Apex, Not the Nodes

Stop looking at the bottom of the branches for signs of flowering. To catch the transition early, look at the apical meristem (the very tip of the main shoots).

What to look for: When the growth at the tip becomes tight, clustered, and intricate, the plant is building its compound raceme. This signals the start of the “stretch.”
Action: This is your last chance to do any final training. Once these tips harden into structure, the plant’s shape is set.

2. Structural Support is Mandatory

Because the plant is about to build heavy, condensed branches, it needs physical support. The architectural shift identified in the study proves that the plant becomes top-heavy.

Action: If you haven’t installed netting (SCROG) or staked your plants, do it immediately. March winds in South Africa can be brutal. Support the structure now, because you won’t be able to lift heavy colas later without stressing the plant.

3. Adjust Nutrition for Branching (Don’t Dump the Nitrogen Yet)

A common mistake in March is cutting out Nitrogen (N) too early and switching straight to a Bloom Booster (P-K).

The Science: Since the transition involves rapid, condensed branching, the plant still requires Nitrogen to build this new structure.
Action: Switch to a transition feed. You need a balanced diet that supports structural growth (Nitrogen) while introducing the Phosphorus and Potassium needed for the early reproductive phase. Starving the plant of N now will result in weak branches that cannot support heavy flowers.

4. Maximise Resin Surface Area

The research noted that glandular trichomes (the resin factories containing THC and Terpenes) appear most profusely on the perigonal bracts (the leaf-like tissue casing the ovary).

The Goal: A healthier architectural structure produces more bracts. More bracts equal more surface area for resin.
Action: Ensure decent airflow and low humidity around your plants. This prevents mould and allows the plant to focus energy on producing these resin-rich bracts rather than fighting off pathogens.

Conclusion: Respect the Architecture

As we head into March, look at your outdoor crop with fresh eyes. They aren’t just “making flowers”; they are rebuilding their entire internal architecture to support the next generation.

By respecting this biological process—supporting the structure, timing your nutrients, and knowing what to look for—you are setting yourself up for a successful, heavy harvest in May.

Happy Growing, South Africa. Let the season begin.

Posted on 18 February 202618 February 2026 by Joe

The Green Giant Visualising South Africa’s Cannabis Appetite

Every day, countless South Africans wake up, grind a bud, and spark a flame. It’s a ritual woven into the fabric of our nation, spanning cultures, classes, and corners of the country. But have you ever stopped to consider the sheer scale of it?

Let’s run a thought experiment. It’s 2026, and we’re standing on the shoulders of data from nearly two decades ago. Back in 2008, estimates put the number of cannabis users in South Africa at around 2.4 million. The world has changed since then. Decriminalisation happened. The culture exploded. Stigma is fading. It’s safe to assume that number has grown significantly, but for the sake of this exercise, let’s stick to a conservative estimate of 3 million users today.

Now, imagine each of those people consumes just one gram a day. That’s a modest average; some smoke far less, others far more. But do the math:

3 million people x 1 gram = 3 million grams of cannabis consumed every single day.

What Does 3 Million Grams Look Like?

Three million grams is 3,000 kilograms, or 3 tonnes.
That number is hard to visualise. So, let’s put it into perspective.

An African Elephant: A fully grown male African elephant weighs about 6 tonnes. So, every two days, South Africa smokes an entire elephant’s weight in weed.
A Toyota Hilux: A double-cab bakkie weighs around 2 tonnes. We are smoking one-and-a-half Hiluxes every day.
A Shipping Container: A standard 20-foot shipping container can hold about 20-25 tonnes of cargo. It would take South Africa just over a week to smoke through a container filled to the brim with cannabis.

This is the daily appetite of a nation. It’s a staggering volume of plant matter being cultivated, harvested, cured, transported, and consumed. And remember, this is likely a low-ball estimate.

The Mystery of the Supply Chain

How did we get here? How does a country produce and distribute 3 tonnes of a flower every day, largely within a legal grey area?

It speaks to the incredible resilience and ingenuity of the cannabis community. Long before the 2018 Constitutional Court ruling, before the “Cannabis for Private Purposes Act,” this network existed. It thrived in the shadows, built on handshake deals and hidden crop fields in the Transkei, the mountains of KZN, and indoor setups in suburban garages.

It is insane to think that despite this massive volume, there are still pockets of our country where access is difficult. There are still people taking immense risks, driving bakkies laden with bags down back roads at midnight, to get this plant to where it needs to be. The sheer logistics of moving 3 tonnes of product daily, without a formal, regulated distribution network, is a marvel of informal economics.

The Bottom of the Bottle?

Here’s the kicker: compared to alcohol, we are still the underdogs. South Africans consume millions of litres of beer and spirits annually. The alcohol industry is a titan, with trucks, warehouses, and tax revenues to match. Cannabis users, despite our numbers, are often still treated as the fringe.

Yet, when you quantify our usage, the reality becomes undeniable. We are not a fringe group. We are a massive, thriving market. We are a demographic that consumes tonnes of product daily.

Room to Grow

It has only been 8 years since decriminalisation began to shift the landscape. In that short time, we have carved out spaces for ourselves. We have cannabis clubs, grow shops, and online communities. We have events like the Amber Cup, celebrating the pinnacle of extraction.

But as we look at the sheer volume, those 3 tonnes a day, it becomes clear how much room there is for improvement. We need better standards. We need quality control that matches the volume. We need a system where access isn’t a gamble but a guarantee.

Currently, the market is a mixed bag. You can find top-shelf indoor hydro in Sandton and bush weed in a matchbox in the rural areas. There is something for everyone, which is beautiful in its own way, but imagine if we could elevate the baseline? Imagine if every one of those 3 million grams was clean, safe, and grown with care.

The Great Cloud

Let’s end our thought experiment with a final image.
If all 3 million of us decided to spark up at the exact same moment, say, 4:20 PM on a Friday, what would happen?

3 million joints are lighting up simultaneously. 3 million lungs exhaling a cloud of blue-grey smoke.

It wouldn’t just be a haze; it would be a weather system. A massive, fragrant cloud drifting over Johannesburg, or blanketing Table Mountain. It would be a visual testament to our numbers, a signal that we are here, we are many, and we are united by this plant.

The market is huge. The potential is limitless. And we are just getting started.

Happy Smoking, South Africa. That’s a lot of weed

Posted on 11 February 202611 February 2026 by Joe

Red Tape on Green Gold: The New Draft Cannabis Regulations & The Fight for Logic

This week, the South African Parliament decided to kick the hornet’s nest. Just as we were settling into the rhythm of the 2026 grow season, the Department of Justice and Constitutional Development (DoJCD) dropped the Draft Regulations for the Cannabis for Private Purposes Act and opened them for public comment.

Naturally, the community is buzzing and not in a good way. The “cot has been turned upside down,” as it were. While I had planned to discuss cultivation techniques today, it is my duty as your weekly commentator to pivot. We need to talk about paperwork, policy, and why the line in the sand is being drawn in some very strange places.

The New Numbers: 5 Plants, 750 Grams

We know that the Cannabis for Private Purposes Act (Act No. 7 of 2024) was signed into law, solidifying our constitutional right to cultivate, possess, and consume in private. However, the regulations, the fine print that tells the police what to look for, were missing. Until now.

Here is what the Government Gazette (No. 50744, published June 2024, open for comment Feb 2026) is proposing:

Cultivation Limit: A maximum of 5 plants per adult in a private place. This applies regardless of the size, shape, or strain of the plant.
Possession Limit: Maximum of 750 grams of cannabis per adult. Crucially, the draft implies this limit applies to both private spaces (your home) and public spaces (what you carry on you).
Transport: You may transport up to 750g, but it must be concealed from public view (in the boot or a storage container).
Vehicles: No smoking in vehicles on public roads. Passengers must conceal their stash. Drivers are essentially obligated to police their passengers.

The Big Question: Where is the Science?

The immediate reaction from the streets is anger. But we need to move past anger into constructive interrogation.

The most glaring issue with these regulations is the arbitrary nature of the limits. As a community, we need to ask the Minister of Justice a simple question, echoed by legal experts and activists alike: What is the scientifically justified rationale behind these numbers?

Why is 5 plants the magic number? If I grow 6 plants to ensure I have a steady supply of medicine for the year, why does that sixth plant make me a criminal?
Why 750 grams? To the uninitiated, or the media outlets running headlines like “Enough for 2,000 joints,” this sounds like a mountain of weed. But any grower knows that wet weight vs. dry weight matters. A massive outdoor tree can yield over a kilogram. Does harvesting one successful plant instantly turn a law-abiding citizen into a criminal because their harvest weighed 800g?

The State must provide a science-based rationale to show that these limitations are necessary and reasonable. Currently, it feels like they pulled numbers out of a hat. We don’t limit how many bottles of wine a connoisseur can keep in their cellar. Why are we limiting the harvest of a gardener?

Apathy is our Enemy

Here is the hard truth: We are letting ourselves down.

I have noticed a trend where the community is quick to complain in WhatsApp groups or Facebook comments, but slow to participate in the actual legislative process. Marching in the streets makes for good photos, but policy is written in boardrooms based on written submissions.

The deadline for comments is 5 March 2026.

There are templates available (like the one circulating from the Cannabis Culture of South Africa) that help you ask these hard questions. They challenge the constitutionality of the police inspecting your private space to count your plants. They challenge the violation of privacy. They challenge the limitation of your right to access health and food (yes, hemp seeds are food).

If we do not flood the Department’s inbox with intelligent, respectful, and firm objections, we are essentially consenting to these arbitrary rules.

The Media Spin

We also have to contend with the media narrative. The headlines focus on the “generosity” of the 750g limit, framing it as a boon for stoners. They fail to understand the agricultural reality.

Furthermore, the regulations around driving are severe. The draft proposes a zero-tolerance approach or extremely low limits for THC in the blood for drivers (comparable to 0.02g alcohol). While we all agree that impaired driving is wrong, we also know that THC stays in the blood long after impairment fades. Are we setting up a system where a daily medicinal user can never legally drive a car, even when sober?

The Reality: The Culture Precedes the Law

Ultimately, we must remember one thing: The Cannabis Community existed before the legislation.

We were growing, sharing, and healing long before the Constitutional Court judgment in 2018. We survived total prohibition. We will survive bad regulations.

However, we shouldn’t have to just “survive.” We should be allowed to thrive. We shouldn’t have to worry that a successful harvest will put us in handcuffs because we exceeded an arbitrary gram count.

The law is trying to fit a square peg (a complex, diverse culture and agricultural crop) into a round hole (a strict, policing-heavy framework). It is up to us to pick up the sandpaper and smooth out the edges.

Do not just read this and scroll on. Find the template. Write to the Department. Ask them why 6 plants are a crime. Ask them to show you the science.

The deadline is 5 March. Let’s make sure they hear us.

Posted on 4 February 20264 February 2026 by Joe

The Budtender Dilemma: South African Cannabis Retail

The cannabis landscape in South Africa is evolving faster than a hydroponic grow cycle. Two years ago, we celebrated the sacred, trust-based relationship between the consumer and their “plug”, a connection rooted in community, reliability, and often, deep friendship. Last week, we explored the booming retail revolution, with neon-lit dispensaries popping up on every corner, navigating the legal grey areas between Section 21 prescriptions and private club memberships.

Today, we need to talk about the crucial link between these two worlds: The Budtender.

As walk-in stores become the new norm, the person behind the counter holds the keys to the kingdom. They are the gatekeepers of knowledge, the curators of experience, and, ideally, the new face of trust. But walk into five different shops today, and you’ll likely get five vastly different experiences. The question we need to ask is: Are we sacrificing connection for commerce?

The Knowledge Gap: When the Vibe Doesn’t Match the Vine

We’ve all been there. You walk into a beautifully designed space, polished glass, slick branding, maybe even a coffee bar in the corner. The vibe is immaculate. But the moment you engage the budtender, the illusion shatters.

Instead of a knowledgeable guide, you’re met with blank stares or generic sales pitches. You ask about the terpene profile of a specific strain, looking for that limonene zest to spark creativity, and you get a shrug. Or worse, you ask for something simple, to just smell the flower, and you’re met with a lecture on cannabinoids you didn’t ask for.

This disconnect is happening too often. The “Green Rush” has brought a wave of enthusiasm, but it has also brought a rush to open doors before ensuring the staff inside are equipped to open minds. It’s akin to walking into a high-end cocktail bar and finding a bartender who doesn’t know the difference between whiskey and gin. If we expect expertise from someone pouring a drink, shouldn’t we demand even more from someone dispensing medicine?

The “Over-Eager” Expert vs. The Overwhelmed Rookie

The problem seems to swing between two extremes.

On one end, you have the Over-Eager Expert. They mean well, armed with buzzwords and rehearsed spiels about the entourage effect and beta-caryophyllene. But sometimes, you just want to buy a gram of something that smells like petrol and pine. The art of budtending isn’t just about knowing facts; it’s about reading the room. It’s about understanding that for some, cannabis is a science, but for others, it’s a simple ritual.

On the other end, we see the Overwhelmed Rookie. Often young, enthusiastic, but thrown into the deep end without a lifejacket. They might be working for minimum wage in a shop struggling to cover its massive overheads. They are tasked with selling a complex agricultural product with medicinal properties, yet they haven’t been given the training or the pay to do it justice.

The Cost of Expertise

Here lies the crux of the issue: Knowledge has a price tag.

True expertise, the kind possessed by the legacy growers and the veteran plugs who have served our communities for decades, is valuable. These are people who understand the plant intimately, who know the difference between a cure that locks in flavour and one that breeds mould. They know their clients’ needs because they’ve built relationships over years, not minutes.

But for many new shop owners, the financial reality of running a legal(ish) dispensary is harsh. Rent, security, licensing (or legal defence) costs pile up. In the scramble to make margins, hiring an experienced, well-paid connoisseur often falls down the priority list. The result? A retail experience that feels transactional rather than transformational.

Bridging the Gap: A Call to Owners and Budtenders

So, where do we go from here?

To the Shop Owners: Your staff are your most valuable asset. Investing in their education is investing in your customer’s loyalty. A beautiful shop might get someone in the door once, but a budtender who listens, understands, and guides them correctly will bring them back forever. Don’t just hire bodies; hire passion. And pay for it.

To the Budtenders: You are the new ambassadors of this plant. Take that responsibility seriously. Learn the difference between Indica and Sativa, yes, but also learn to listen. If a client wants to know about terpenes, geek out with them. If they just want to smell the jar and buy a pre-roll, respect that ritual. You are the bridge between the grower’s hard work and the consumer’s experience.

To the Community: Be patient, but be discerning. Support the shops that get it right. If you find a budtender who knows their stuff, who treats you with the same warmth and respect as your old plug, which in all fai hold onto them. Tell the owner. Let them know that expertise matters.

The transition from the street corner to the storefront was never going to be seamless. But if we want the South African cannabis industry to thrive, to be more than just a cash grab, we need to ensure that the heart of the culture, the human connection and deep respect for the plant, remains beating behind every counter.

Posted on 28 January 202628 January 2026 by Joe

Vaporising the Myths: A Deep Dive into Cannabis Vape Quality

Last week, we confronted the synthetic ghost of HHC haunting our shelves. A sobering reminder that not all cannabis products are created equal. This encounter naturally leads us to a broader, equally critical conversation: the world of cannabis vape cartridges.

Vaping has exploded in popularity, offering a discreet, convenient, and potent way to consume. But walk into any dispensary, and you’re met with a dizzying array of options. “Live Resin,” “Live Rosin,” “Distillate,” “Full Spectrum” the labels can be confusing. And let’s be honest, sometimes the experience is a letdown. A cart that tastes like artificial candy, leaks, or simply doesn’t deliver the promised effects can turn anyone off.

This week, we’re pulling back the curtain on vape production. We’ll explore the science of extraction, specifically fractional distillation, decipher the differences between premium and subpar products, and arm you with the knowledge to make better decisions. Because when it comes to vapes, knowing how it was made is just as important as what is in it.

The Engine of Consistency: Understanding Fractional Distillation

At the heart of most commercial vape cartridges lies a process called fractional distillation. It sounds complex, but the concept is straightforward. Imagine a sophisticated refinery for cannabis oil.

How it Works:
Fractional distillation separates the various components of crude cannabis oil based on their unique boiling points. The crude oil, often extracted using methods like CO2 or ethanol, is heated. As the temperature rises, compounds vaporise at different points.

Volatiles first: Lighter compounds, including some terpenes and solvents, boil off first.
The Goldilocks Zone: The process is tuned to target the boiling point of cannabinoids like THC or CBD.
Condensation: These specific vapours travel up a fractionating column, cool down, and condense back into a highly purified liquid.

The Result:
This method is incredibly effective at isolating specific cannabinoids, often achieving purity levels of 90-99%. It removes impurities, fats, waxes, and chlorophyll, resulting in that clear, golden oil we often see. This allows manufacturers to create products with very precise, standardised potency. A huge plus for consistent dosing.

The Catch:
While great for potency, fractional distillation has a downside: it strips away the plant’s soul. By isolating THC or CBD, the process often removes the original terpenes and minor cannabinoids that contribute to the “entourage effect” and the strain’s unique character. The resulting distillate is a blank slate, potent but flavourless and lacking the nuance of the original plant.

This is why, with pure distillate, it is impossible to know which plant material or strain was actually used. The unique fingerprint of “Durban Poison” or “White Widow” is largely erased in the pursuit of pure THC.

The Flavour Factor: Reintroducing Terpenes

To make this tasteless distillate enjoyable (and to mimic specific strains), manufacturers must reintroduce terpenes. This is where the quality divide widens significantly.

Botanical-Derived Terpenes (BDT): These are terpenes extracted from other plants (like lemons for limonene or lavender for linalool). They are cheaper and can create specific flavour profiles, but they often lack the complexity of cannabis. This is where you get vapes that taste like “Blueberry Blast” or “Mango Madness” flavours that don’t exist in the cannabis plant naturally.
Cannabis-Derived Terpenes (CDT): Premium brands will reintroduce terpenes extracted directly from cannabis. This offers a more authentic taste and potentially a better effect, but it’s still a reconstruction of the original profile.

My Rule of Thumb: If the flavour doesn’t exist in nature (like “Bubblegum Ice”), I steer clear. I want my cannabis vape to taste like cannabis.

The Premium Tier: Live Resin and Live Rosin

For those seeking the truest expression of the plant, Live Resin and Live Rosin vapes are the gold standard. These aren’t made using fractional distillation.

Live Resin: Made from fresh-frozen plant material (not dried and cured) using hydrocarbon extraction (like butane). Freezing preserves the volatile terpenes that are usually lost during drying. The result is a potent oil that captures the true aroma and full spectrum of the living plant.
Live Rosin: The pinnacle of purity. This is a solventless extract made by pressing fresh-frozen bubble hash under heat and pressure. It retains the maximum amount of terpenes, cannabinoids, and flavonoids without any chemical solvents. It is the closest experience to smoking the actual flower, offering a robust, complex high.

These products prioritise the entourage effect and the unique terroir of the cultivation, offering a depth of experience that distillate simply cannot match.

The Hardware Hazard: Why Your Cart Matters

It’s not just about the oil; the vessel matters too. A premium extract in a cheap cartridge is a waste.

Plastic is a No-Go: Avoid cartridges with plastic tanks or airways. Terpenes are solvents themselves and can degrade plastic over time, leeching harmful chemicals into your oil.
Ceramic and Glass: Look for carts made with glass tanks and ceramic heating elements. These materials are inert, preserving the flavour and ensuring you’re inhaling only the vaporised oil, not burning wicks or melting plastic.
Airflow: A good cart should have decent airflow to prevent clogging, a common issue with thick oils.

Empowering Your Choice

So, how can you use this knowledge?

Ask Questions: When buying a vape, ask, “Is this distillate, live resin, or live rosin?” Asking “Are the terpenes cannabis-derived?” is a great follow-up.
Read the Label: Look for information on the extraction method. “Solventless” usually points to Rosin. “CO2 extracted” or “Ethanol extracted” often implies a distillate base, though not always.
Trust Your Senses: If it tastes artificial, it likely is. If it makes you cough excessively or feels harsh, the hardware or the starting material might be subpar.
Value the Source: Remember, with distillate, the origin strain is often lost. If you care about terroir and specific strain effects, lean towards Live Resin or Rosin, where the plant’s identity is preserved.

Vaping can be a fantastic, clean way to enjoy cannabis. By understanding the difference between a mass-produced distillate and a crafted live extract, you can ensure your hard-earned money goes towards a quality experience that respects the plant we love.