Fertilizing cannabis plants is a crucial part of successful cultivation that is often underestimated. A balanced supply of nutrients not only ensures healthy growth, but also has a direct impact on yields and the quality of the final product. In this blog post, we give you an overview of the most important nutrients that cannabis plants need, how to use them correctly, and what you need to pay attention to in order to achieve the best results.
1. Why is fertilization important?
Cannabis plants require a variety of nutrients to grow optimally in all phases of their life cycle. These nutrients are often present in limited quantities in the soil, which is why additional fertilization is necessary. Proper fertilization helps the plant focus its energy on important development processes such as root formation, flowering, and the production of terpenes and cannabinoids.
2. The most important nutrients for cannabis
Cannabis requires several macro and micronutrients, which are needed in different amounts at different stages of growth. The main nutrients required for the healthy growth of cannabis plants are:
- Nitrogen (N): Promotes vegetative growth, i.e. the growth of leaves and stems. Nitrogen is particularly important during the growth phase.
- Phosphorus (P): Supports the development of roots and flowers. Phosphorus is needed more during the flowering phase.
- Potassium (K): Promotes overall plant health, water supply and disease resistance. Potassium is important in all phases, but especially during flowering.
In addition to these macronutrients, there are also micronutrients that are needed in smaller quantities but are just as crucial for plant health:
- Calcium (Ca): Supports cell wall structure and stability.
- Magnesium (Mg): Essential for photosynthesis.
- Sulfur (S): Important for the formation of amino acids and proteins.
And micronutrients such as iron, zinc, manganese and boron should not be neglected.
3. Phases of Fertilization
The needs of a cannabis plant change over the course of its life cycle, which is why fertilization must also be adapted. Here is an overview of what fertilization looks like in the different phases:
a) Seedling and vegetation phase:
During this phase, the main focus is on the growth and development of the root system and the green parts of the plant. Nitrogen is particularly needed here to promote strong leaves and healthy shoots. Phosphorus is also needed in moderate amounts to support healthy root growth.
- Recommended nutrients: High nitrogen content, moderate phosphorus content, balanced potassium amount.
b) Flowering phase:
During the flowering phase, the plant's nutrient requirements change. The focus is now on flower formation and bud development, which is why a higher proportion of phosphorus and potassium is required. Too much nitrogen can lead to an unwanted growth phase and inhibit flower formation. It is important to adjust the fertilization so that the plant can use enough energy for flowering.
- Recommended nutrients: More phosphorus and potassium, less nitrogen.
c) Harvest phase:
In the last weeks before harvest, reduce fertilization, especially nitrogen. This helps the plant to concentrate on the final ripening process. It is also a good time to resort to organic fertilizers such as molasses or special flushing liquids to remove excess nutrients from the soil and improve the taste and quality of the flowers.
4. The right amount and frequency of fertilizer
Too much fertilizer can be just as harmful as too little. Over-fertilization can cause nutrient burn, which damages plants and can reduce yield. It is important to find the right dosage, which can vary depending on the nutrient concentration and the specific needs of the plant.
- Start with low doses: Start with a lower concentration and slowly increase it when you see that the plant responds well.
- Use an EC meter: An EC meter measures the electrical conductivity of the water and helps monitor nutrient concentration. This is especially important to avoid over-fertilization.
Frequency of fertilization:
- During the vegetative phase, fertilization can be done every 1-2 weeks.
- During the flowering phase, it may be useful to fertilize every 1-2 weeks, but at the same time pay attention to the plant for possible signs of nutrient deficiency or excess.
5. Types of fertilizers for cannabis
There are two main types of fertilizers you can use when growing cannabis:
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Liquid fertilizers: They are easy to use and are mixed directly into the water used for irrigation. They work quickly and can be adjusted as needed.
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Granular fertilizers or organic fertilizers: These are slower-acting and are good for use in the soil. They release their nutrients over a longer period of time and do not need to be applied as frequently.
Organic vs. Mineral Fertilizers:
- Organic fertilizers such as compost, worm castings or guano promote a healthy soil microbiome and are more environmentally friendly, providing a slower but sustainable source of nutrients.
- Mineral fertilizers are fast-acting and provide a direct source of nutrients, but can cause soil imbalance if not applied correctly.
6. Conclusion: Patience and observation are the key
Fertilizing cannabis plants is an art that requires experience. Each plant is unique and responds differently to different nutrients and amounts. It is important to observe your plants carefully and adjust the fertilization according to their needs. With the right nutrient supply, you can grow healthy, strong plants that produce abundant flowers with high quality and yield.
Remember that the quality of your cannabis product depends not only on the right fertilization, but also on factors such as light, temperature, humidity and the type of cultivation. If you balance these factors, nothing will stand in the way of your success as a grower!
Good luck fertilizing and growing your cannabis plants!