Over the past weeks, we’ve covered a wide range of foundational topics for cultivating thriving cannabis plants, from composting to plant training. This week, we’re honing in on a crucial part of the cultivation process: watering and nutrient management. Proper watering and a balanced nutrient approach are essential for promoting healthy growth, enhancing cannabinoid yield, and achieving optimal plant health.
Let’s dive into best practices for watering cannabis and managing nutrients, from understanding NPK ratios to maximizing the benefits of organic fertilizers and biostimulants like humic acid.
The Essentials of Cannabis Watering: Striking the Right Balance
Water is the lifeline of your cannabis plants, but too much or too little can hinder their growth. Overwatering is a common mistake, leading to root rot and nutrient lockout, while underwatering stresses the plants, limiting their nutrient uptake and development. I normally will say to guys just starting. To lift their pots and feel the weight. Do this before watering and after watering. This will give you an indication of the amount of water content present in the pot. When you check upthe next day or two on your plants when you lift the pots up you will notice the difference in weight which would translat back to the amount of water the plants absorbed over the period of time.
Watering Best Practices:
Frequency and Amount: The amount of water needed depends on factors like growth stage, plant size, and environment. As a general rule, water deeply but less frequently, allowing the soil to dry slightly between waterings.
Monitor Drainage: Cannabis plants require well-drained soil to prevent waterlogging. Ensure your pots have sufficient drainage and consider using a soil mix that retains moisture without becoming waterlogged.
pH Levels: Maintain a water pH of 6.0–6.5 for soil-grown plants and 5.5–6.0 for hydroponics. Adjusting pH as needed prevents nutrient lockout and ensures your plants can absorb essential minerals efficiently. In the future we will dive into Ph more. I have written on this topic in my ‘ pH doesn’t matter’ blog.
Managing Nutrients: The NPK Foundation
Nitrogen (N), Phosphorus (P), and Potassium (K)—collectively known as NPK—are the primary nutrients cannabis plants need throughout their growth cycle. Each element plays a specific role:
Nitrogen: Crucial for leaf and stem development, especially during the vegetative stage. Adequate nitrogen supports lush, green foliage that maximizes photosynthesis. Most times we are over feeding nitrogen at the incorrect times of the plant’s growth. To ensure you do not over feed. A good rule of thumb is always, Less is more. So, by halving your Nitrogen inputs you can ensure that the plants still receive the crucial Nitrogen they require.
Phosphorus: Supports root development and is vital during the flowering stage for energy transfer and bud formation. Very Airy flowers are often a result of a lack of Phosphorus inputs. During the flowering period, growers need to focus on ensuring that phosphorus is getting to the plant as intended.
Potassium: Enhances overall plant health, helping with water absorption, nutrient transport, and disease resistance.
During the vegetative phase, cannabis requires a higher nitrogen concentration to support rapid leaf and stem growth. When shifting to flowering, reduce nitrogen and increase phosphorus and potassium for optimal bud development and potency. Some growers like to flush nutrients out of their pots to ensure that no excess nitrogen nutrient remains present during the transition period of the plants.
Enhancing Nutrient Uptake with Humic Acids and Biostimulants
Humic acid is a powerful biostimulant that promotes nutrient uptake and enhances soil structure. Studies show that humic acid boosts microbial activity in the soil, making nutrients more available to plant roots and also improving nutrient absorption efficiency, allowing plants to make the most of each feeding.
Biostimulants can be added as part of a regular nutrient regimen or mixed into the soil before planting. For cannabis, humic acid supplements encourage stronger roots, faster growth, and greater tolerance to environmental stressors.
Organic Fertilisers: Sustainable Choices for Healthier Plants
Organic fertilisers provide essential nutrients slowly, enhancing soil health over time and supporting beneficial microbial activity. A recent study found that organic fertilizers improve overall nutrient balance, especially during the flowering stage, where they enhance cannabinoid production and bud density organic fertiliser Options for Cannabis:
Compost and Manure: These are high in organic matter and beneficial microbes, gradually releasing nutrients. Please make sure to read last weeks Composting blog to learn more about how to handle raw manure and more.
Fish Emulsion: Rich in nitrogen, it is especially beneficial during the vegetative stage.
Seaweed: Another amazing source of Nitrogen for plants as well as hormones to stimulate growth.
Bone Meal: A source of phosphorus for root development and flowering.
Combining organic fertilisers with humic acid creates an environment that supports robust, resilient plants. Organic amendments also provide a long-lasting nutrient reservoir, reducing the need for frequent feedings.
Many of these including the Natural Farming techniques we have previously discussed are all valid inputs to achieve healthy organic flowers.
Watering and Feeding Schedule: Tips for Consistency
Creating a consistent schedule helps you avoid over- or under-watering and ensures your plants receive balanced nutrients throughout their life cycle.
Many growers rely on an automatic watering system, some have drip lines and others have flood and drain systems. Even thought this will take the work out of watering plants. It still requires growers to be attentive and aware of drip rates, nutrient mixtures and potential leaks that can cause damage. Just looking at the agricultural industry as a whole will unlock any and all types of irrigation for you. So if you wish to go this route, you need to just take some time. Plan everything correctly and go for it. Irrigation systems are often very simple. Opening and closing of valves can easily be implemented to manually control the flow of fertigation.
Suggested Schedule:
Vegetative Stage: Feed plants every 1–2 weeks with a balanced NPK formula, keeping nitrogen levels high. Water deeply, allowing the soil to dry between sessions. Monitor the soil moisture, during this period plants tend to take up the water a little bit faster, generally, there is also more intense sun during this stage.
Flowering Stage: Shift to a lower nitrogen mix with increased phosphorus and potassium. Add organic fertilisers to enhance soil health and cannabinoid production, supplementing with humic acid biweekly for nutrient uptake. Along with Humic acids are many other biostimulants that can add great benefit to your flowering cycle. It is important to note, however, that taking things too far at this point in time will drastically change your plant’s flowers. Be mindful of the extras you add during this time.
Final Thoughts: Optimize Watering and Nutrients for Vibrant Cannabis Growth
Watering cannabis and managing nutrients effectively is an art that takes practice. By understanding NPK ratios, incorporating organic fertilisers, and leveraging biostimulants like humic acid, you can create an environment where your cannabis plants thrive. Consistent attention to watering and nutrient balance will lead to healthier plants, higher cannabinoid yields, and ultimately, a successful harvest.
Reach us on WhatsApp