Cannabis nutrients are broken into 3 categories; primary macronutrients, secondary nutrients and micronutrients. They are deemed as such based on the amounts required by your plants’ diet. The primary macronutrients are what your plants depend on the most and they include nitrogen, phosphorus, and potassium. N-P-K fertilizers are a fundamental part of your cannabis garden’s feed regimen and here’s why.
The Importance of Nitrogen in Photosynthesis
Despite the fact that more than 75% of the air around us is comprised of nitrogen, plants can’t absorb it through the air. Nitrogen is naturally occurring in soil and can be found in high concentrations in the decaying plant matter that many organic farmers turn into compost. Acting as a fundamental building block of plant proteins including cell structures and genetic material, nitrogen plays a crucial role in photosynthesis. It actually comprises approximately 4% of the mass of the plant making it the most abundant element in cannabis and most green plants by far. Nitrogen is essential to photosynthesis. When nitrogen is in short supply, newer leaves will steal what they can from the older leaves, leaving them yellow and wilted.
Phosphorous’ Contributions to Genetic Coding
Phosphorous is the next primary macronutrient. Much like nitrogen, it plays a vital role in photosynthesis and in the creation of new plant cells. Phosphorus is one of the primary components of plant gees and chromosomes that carry with it the blueprint for the genetic code. It also facilitates the transfer of genetic material from one cell into newly formed cells. Deficiencies in phosphorous are difficult to diagnose and are often only observed by stunted plant growth. This alone can make a diagnosis a challenge as there are many factors that can lead to reduced growth. In extreme cases, purple spots may appear on the leaves, but there’s no reason to ever let it get this far.
The Regulating Power of Potassium
Potassium is a key nutrient that helps to regulate the intake of carbon dioxide. It also plays a vital role in the transpiration of water up through the roots and out through the pores on the leaves known as stomata. It also helps to activate enzymes that are responsible for plant growth. Potassium plays a role in strengthening cell walls, making deficiency fairly easy to spot. Deficiencies of potassium can cause a yellowing or even a whitening of leaves and may result in cankers forming on the surface of the leaf. This is due to a breakdown in the cellular structure. Leaves will tend to curl under and symptoms can sometimes be confused with heat stress. If your stems become stiff and brittle, this is another sign you may have a potassium deficiency.
Which NPK Ratio is Right for Your Growth Stage
When looking at NPK fertilizers, you will see a series of numbers on the bag which represents the ratios of nitrogen, phosphorous and potassium. You might find 10-10-10, which is a 1-1-1 ratio or a 5-10-10, which is a 1-2-2 ratio. The amount of each nutrient your plant requires will greatly depend on the stage of growth. Early vegetative plants require twice as much nitrogen as phosphorous so a 2-1 ratio is desired. Once you move into flowering stages, the amount of phosphorus will increase. You should use ratios with twice as much phosphorus to nitrogen in early flowering and just under 3 times the ratio in mid flowering plants. As you approach the late stage, you can decrease you phosphorus back to a 2-1 P to N ratio. Find out the needs of your strains and design a feed regimen that will keep your NPK levels up to snuff and your plants happy and green.