To provide the best yield possible, cannabis plants need a healthy, varied diet. With the information and tips in this guide, growers can minimize the risk of nutrient deficiencies and quickly resolve them if they occur. Whether you grow sativa weed seeds or indica weed seeds purchased online from our seedbank, or have another popular strain of marijuana seed that you’ve obtained from another grower, these tips should apply to all types of medical cannabis seeds and industrial hemp nutrition as well.
Just like people do, marijuana plants need a healthy diet that’s full of variety. They need nutrients in the right quantities to fulfill crucial physiological functions, and if there’s a deficiency in any area, growth and yield will be affected.
Fortunately, most cannabis plants like candy cream and the strawberry cheese strain do an excellent job of telling growers what they need. If a nutrient deficiency occurs, a plant may wilt, curl its leaves, or become discolored. With these signs, the cultivator can determine what the plant requires. Before we get into the prevention and resolution of various nutrient deficiencies, though, there are a few things you should consider.
A macronutrient is a mineral that plants need in significant quantities. Macronutrients include potassium, phosphorus, and nitrogen. Just like protein, fats, and carbohydrates form the basis of the human diet, cannabis plants need the above minerals to perform crucial processes.
Micronutrients are elements in minerals used in smaller quantities, but that doesn’t make them any less important to the plants’ health and vitality. Micronutrients include boron, iron, sulfur, and zinc, among others. They’re best thought of as being like vitamins and minerals in our diet. We don’t require much, but a deficiency can cause serious problems.
Distinguishing between immobile and mobile nutrients can help a cannabis cultivator diagnose deficiencies accurately. A mobile nutrient is a mineral that is carried throughout a plant to the parts that need it the most. For instance, the phosphorus in old fan leaves may be diverted toward new growth in the event of a deficiency. Therefore, these deficiencies may first be detected in old growth.
An immobile nutrient is held in place and the plant cannot redistribute it. For instance, if there’s a zinc deficiency, the signs will appear in new growth as the cannabis plant can’t divert its stored minerals.
Mobile nutrients include:
The following nutrients are immobile:
Read on to learn how these nutrients, plus soil pH, can affect plant health.
A garden can have nutrient-rich soil, but the plants won’t be able to absorb those nutrients if the growth medium’s pH is incorrect. Cannabis plants do best at a pH of 6.0-6.5; anything above or below that will make it difficult for the plants’ roots to absorb crucial nutrients. This phenomenon is referred to as nutrient lockout, but routine system flushes can prevent it. Use a pH meter to measure levels frequently, and if necessary, change the pH of the soil with the following technique.
Developments in soil technology have demonstrated that the root zone or rhizosphere is teeming with life. In the root zone, an intricate network of microscopic life works in synergy with the roots. The soil requires the right balance of fungi and bacteria to degrade organic material and unlock nutrients for the plants to absorb.
Through composting, a grower can build living soil that prevents nutrient deficiencies and supports biodiversity within the root zone. With this practice, your soil will be full of the beneficial life that helps keep plants healthy and increases yields.
However, a grower can also take direct, short-term action. Spraying nutrients on the foliage is a quick fix when cannabis plants are running short. When nutrients are given in this manner, they bypass the roots and are taken in through the plants’ leaves.
Now that you’ve learned how to control soil pH with natural methods, let’s discuss how to stop and resolve nutrient deficiencies.
Below you’ll find a list of the most common nutrient deficiencies encountered by cannabis cultivators, as well as tips on preventing them and fixing them if they arise.
Most organic fertilizers have enough nitrogen to resolve a deficiency. Manure, alfalfa, feather meal, and fish meal are all great choices for a cannabis garden. Check and adjust the soil’s pH as needed and consider applying compost tea to the foliage for a quick fix. Increase the nitrogen content of your compost by adding fresh cuttings, grass clippings, and kitchen scraps.
Fix the deficiency by bringing the growth medium’s pH up to the high end of the normal range, as this makes it easier for plants to absorb phosphorus. Adding fish meal and worm castings to the soil may also help, as will the use of a high-phosphate organic fertilizer. Overwatering is a common problem, but it’s easily solved. Water the plants only when the top inch of the soil is dry. If possible, move the plants to a warm spot or put up a tarp to hold in heat. Cannabis plants find it difficult to absorb phosphorus in temperatures below 59 degrees Fahrenheit.
Once a deficiency has arisen, resolve it by flushing the growth medium. Next, measure the pH and adjust it to correct a potential nutrient lockout. Add some chicken manure to the soil and spray the foliage with an organic seaweed solution.
Resolve a calcium deficiency with a calcium/magnesium supplement and regular pH monitoring. Finally, water your plants with a solution of one teaspoon of lime to four liters of water.
Fix a sulfur deficiency with Epsom salts. Add one or two teaspoons of salt to four liters of water and supplement the plants until the symptoms go away. Adjust the growth medium’s pH if necessary.
Stop a magnesium deficiency by flushing the growth medium with 6.0 pH water if needed. Epsom salts are a rich source of magnesium; make a solution of one or two teaspoons of Epsom salts and four liters of water and apply it to your plants until the symptoms disappear.
Fix an iron deficiency by keeping the growth medium’s pH in the appropriate range. Flush the medium and use an iron-containing supplement afterward. Use nitrogen fertilizer to reduce pH and make iron more readily absorbable.
Fix a deficiency by flushing the growth medium and keeping it within the appropriate pH range. Combine one teaspoon of boric acid with four liters of water and apply it to the affected plants.
Resolve a molybdenum deficiency by flushing the growth medium and adjusting its pH as necessary. Spray affected areas with an organic seaweed solution and water the plants with compost tea containing worm castings.
Once a zinc deficiency sets in, it can be cured by reducing the growth medium’s pH to the correct level. Don’t overwater your plants and apply a seaweed- or fish-based foliar spray to increase zinc levels quickly.
Though cannabis plants only need some of these nutrients in small amounts, a deficiency can cause big problems. By learning to recognize the signs of a nutrient deficiency and taking prompt action when problems arise, growers can ensure the health and high yield of their cannabis crops. Another way to growers to reduce the maintenance needs of their plants is to purchase easy to grow strains such as Auto Gorilla Glue 4 or Zkittles from a highly reputable seed bank such as I49 to ensure superior genetics.