If you’re new to the world of cannabis cultivation, figuring out things like lighting, medium, set-up, growing methods, etc. can feel overwhelming to the point of discouraging. Then, to top it all off, once you’ve sorted out all of those items, there are nutrients for cannabis to figure out! As such, in order to help make the cultivation process as easy as possible, here is a primer on nutrients.
The Best Nutrients for Cannabis Cultivation
As you know, successfully growing most anything requires more than just water; the same applies when cultivating cannabis–plants need nutrients in order to thrive. In short, a cannabis plant has two major stages in its lifespan–the vegetative stage and the flowering stage–and each stage will require different nutrients for cannabis. Fortunately, it’s relatively easy to purchase various nutrient products from numerous companies that specialize in this field. Provided below is a brief rundown of what kind of information to look for when reading nutrient product labels.
NPK: Nitrogen (N), Phosphorus (P), and Potassium (K)
The numbers provided with each letter tell you the percentage of each nutrient in the product. For example, NPK 9-5-8 means that the fertilizer contains 9% nitrogen, 5% phosphorus, and 8% potassium. The slightly confusing part is this: there’s no one exact and perfect NPK formula, so you will see different ratios for different products. What matters is maintaining the balance of NPK for your cannabis plant as opposed to finding the “correct” formula. So, for example, an all-purpose fertilizer where the NPK is equal (i.e. NPK 20-20-20) won’t give your cannabis plants what they need. Instead, the general rule of thumb for figuring out which NPK ratio is the best for your cannabis plants is as follows: fertilizers with a higher percentage of N and lower percentages of P and K are generally meant for a cannabis plant’s vegetative stage. Those meant for the flowering stage will have a lower percentage of N and higher percentages of P and K.
Soil or Hydro
Not only is checking the NPK ratio important before buying fertilizer but so is making sure to find out if the solution is made for the growing medium of soil or hydroponic. The nutrients for cannabis for these two mediums are not the same.
Ingredients: Organic vs Chemical
While two different fertilizer products by two different companies might have the exact same NPK ratios, their ingredients are sure to differ. In essence, the ingredients will let you know if you’re getting a chemical or an organic nutrient solution. In terms of achieving successful cultivation, whether you choose chemical or organic fertilizer is more about personal preference as both kinds will work well when properly used. The major difference between organic and chemical solutions is that the first is much more environmentally friendly and often contains animal manure, which requires composting before usage. Organic fertilizers do tend to take longer to break down into the soil in order for the plants to be able to utilize them than chemical ones. Meanwhile, chemical solutions, which can be immediately taken in by your plants, are made of synthetic products that are obviously not as good for the environment. Another thing to note when using a chemical fertilizer is that you could either end up with nutrient burn or nutrient excess. As such, most expert breeders recommend that along with carefully following the instructions provided on the packaging, consider starting with an even smaller amount and then slowly increasing it over time.
Nutrients vs Supplements
If a solution has a very low percentage of NPK (i.e., .1 – .2 – 1.5) then this isn’t a fertilizer with nutrients but is a supplement, which can be used to improve the soil or aid plants in their growth or yield size. A good place to start is to have one main fertilizer for the vegetative stage and the flowering stage. Once you’ve solidified this, you may want to add supplements, but do not use them in lieu of fertilizer, otherwise, your plants will be sure to be lacking in all the NPK it needs. One other tip is that regardless of the brand or company you decide to go with, it is best to use the same brand for both your nutrients (fertilizer) and supplements.
Nutrient Schedule and Conclusion
Lastly, let’s go over when to use nutrients for cannabis at a certain stage. Once your seeds are germinated and your plants have produced anywhere from 2-3 sets of leaves, you can start to feed them nutrients. Some brands will say on their product to start 1-week post-germination in the seedling stage, which is also fine to do. Just make sure that no matter what, you carefully read and follow the instructions so as to not end up with a nutrient burn. The instructions on the fertilizer that you choose will also let you know if you need to use the nutrients every time you water or not, and/or exactly when to fertilize your plants.
Nutrients for Cannabis at the Vegetative Stage
This stage usually runs anywhere from 4-12 weeks, if not longer. This is when your cannabis plants will need the most light and NPK, and this is the time when they will need especially high percentages of nitrogen.
Nutrients for Cannabis at the Flowering Stage
The flowering stage of cannabis plants is when their buds or flowers begin to grow. This is the time when the plants will require a lot of P and K, and less N, which is why you need a fertilizer that is specifically made for this growth stage. Making sure that your cannabis plants are getting the right amounts of NPK during this stage should result in a healthy, maximum-yielding crop. While there is so much more that could be said about fertilizers (i.e., macronutrients vs micronutrients and secondary micro and macronutrients, etc.), these basics should be enough to give you the foundation you need to begin the exciting journey of being a cannabis cultivator.
