With more and more states legalizing cannabis use, interest surrounding proper growing methods has certainly increased and expanded. In order to grow quality plants, many growers add nutrients to their cannabis crops. However, they could be doing more harm than good. Between the wide variety of nutrients available and the vast plethora of information about them, it can be overwhelming, especially for those who are new to the scene.
We need to determine what nutrients are best to feed your plants and not cause any harm. We also need to maintain a proper feeding schedule. We’re going to dive into the world of growing cannabis, understanding how these plants absorb and use their nutrients, and how much of what nutrients they need to thrive.
What Do Cannabis Plants Need to Thrive?
In order to survive, grow, and thrive, cannabis plants need nitrogen (N), phosphorus (P) and potassium (K). Throughout the life of your cannabis plant, however, they’ll need varying amounts of these nutrients, but we’ll dig deeper into that later. In addition to these three elements, your cannabis plants will need calcium, sulfur, and magnesium, these are called ‘trace elements’ or ‘micronutrients,’ and they can be obtained from the soil, as well as oxygen, carbon, and hydrogen.
Many nutrient solutions, fertilizers, and other additives often contain other mineral nutrients referred to collectively as micronutrients or trace elements because they use them in much lower quantities as less is needed for the health of your plants. These nutrients typically contain some combination of the following: zinc, molybdenum, iron, chlorine, manganese, cobalt, boron, silicon, and copper. Although cannabis crops require very low concentrations of these micronutrients, they are still vital elements to your plants’ chances of survival and growth.
How to Properly Feed Your Cannabis Crops in All Three Stages of Life
Plants, much like animals, go through different stages of life where they require different nutrients to grow and thrive. The first stage of life for your cannabis plants is the seedling stage; your plants require little more than to be properly planted in quality soil in a pot large enough that the roots have room to grow freely and that the soil has access to plenty of humidity.
If you’re growing cannabis in artificial mediums that don’t have the natural nutrients of soil, you may need the help of seedling nutrition and root boosters to help provide the proper nutrients for the seedling stage. These root boosters provide your plants with bacteria, enzymes, and other compounds created to encourage the growth and health of the plants’ roots. Seedling nutrients have the correct portions of potassium, nitrogen, and phosphorus for healthy sprouts. You can achieve a similar effect by using a feed during the vegetative stage. It’s important to note, however, that you’ll need to reduce the dosage if it’s not a fertilizer specifically made for cannabis.
The next stage of life for your cannabis plants is the vegetative stage. During this stage of growth, your plants will need more nitrogen and potassium and a medium amount of phosphorus. The typical rule of thumb to get the concentration right is as follows: potassium levels during the vegetative stage can vary from a third to a half the amount of nitrogen in the fertilizer or nutrient, while the amount of phosphorus should be about half the amount of nitrogen present.
When choosing the right fertilizer, you should look for the three numbers, separated by dashes, that can be found on the front of the fertilizer bag or bottle of nutrients. These numbers stand for N-P-K and indicate the amounts of nitrogen, phosphorus, and potassium present in the nutrients. For example, a fertilizer with 8-5-5 on the package has 8% nitrogen, 5% phosphorus, and 5% potassium by weight. You should pay close attention to the recommended doses of these and always err on the side of caution to keep from damaging your plant.
When your plant is ready to transition into the next stage, flowering, it’s important for you to reduce your nitrogen levels drastically, while simultaneously increasing the phosphorus levels and maintaining the same amount of potassium that you were using in the vegetative stage. For this stage, you’ll want to use a ‘bloom nutrient’ formula that has lower levels of nitrogen in it. The ideal time to start using bloom nutrients is when the buds start to take form. This will ensure that your plant gets enough phosphorus and potassium for healthy bud growth and development without overloading it with nitrogen.
The proper amount of phosphorus can increase the number of flowers, while the bulk weight of the flowers can be assisted by proper potassium intake. However, if you go overboard with either of these, you can burn and ruin the plant, so be careful.
In the flowering stage, you want to be sure not to go overboard with the nitrogen, because it can cause an unpleasant taste in the buds as well as discourage their development. It’s typically not a good idea to use a general purpose plant nutrient during the flowering stage, as they tend to have too much nitrogen present in their mixtures for this stage of the plants’ lives. It’s crucial that you avoid time-released nutrients, such as a fertilizer spike, slow-release fertilizer, or Miracle-Gro, due to their tendency to deliver too much nitrogen in this crucial stage.
Concerns of Under- or Overfeeding
When it comes to feeding your cannabis plants the proper doses of nutrients, caution is key. You should always start slowly with smaller doses and work your way up, so you don’t risk damaging or killing your plants. Those cannabis plants that grow in small amounts of added nutrition tend to grow healthier, thrive better, and produce a better yield than those grown in over-fertilized soil. A good rule of thumb is to add nutrients to the water every other time you irrigate your cannabis crops. If you’re unsure or uneasy about the proper dose to use, use half the amount recommended on the packaging to stay on the safe side.
If you’re concerned about overfeeding, there are a few signs for which you can keep an eye out. The most visible and indicative signs of a nutrient imbalance in the cannabis crops are the following: drooping, yellowing, or irregularly-shaped leaves; irregular leaf dimensions; burnt edges; or brown spots. However, it’s important to note that yellowing leaves can merely signal a potential problem within the vegetative and early flowering stages and can normally occur towards the end of the flowering stages.
If you find it difficult to resolve a nutrient issue, you can try to flush the soil with pure, neutral pH water for a few days, trying again with a half dose of your chosen nutrient mix. Removing the top section of the soil (only a few centimeters is necessary) will take care of the extra nutrients, giving you a clean slate with which to work. Obviously, this is a drastic step that should be avoided whenever possible. Nutrient mistakes can cause irreparable damages and greatly affect your product yield, so be sure to err on the side of caution when determining the proper doses to administer.
The Role pH Plays
A big source of nutrient deficiencies, especially for new growers, is neglecting to check the pH of the soil. Despite having nutrient levels exactly right, a problem with the pH could still result in nutrient imbalance because it can ’lock’ the soil and prevent the plant from absorbing the nutrients at all.
The ideal pH for cannabis grown in soil is in the six to seven range, while that of those grown through hydroponics, coco coir, or another soilless medium tends to be within the five-and-a-half to six-and-a-half range. If you find there’s a problem with your pH, you can use either the product pH UP or pH Down in either soil-grown or hydro-grown plants to get the pH back on track. Make sure you test your pH only after you’ve added your nutrients, as they will affect the pH, thus affecting any adjustments you might need to make.
Organic Nutrients vs. Chemical Nutrients
The ultimate question with nutrients for new growers seems to be whether to take the organic or chemical route. The truth is that one isn’t actually any better than the other. Both organic nutrients and chemical nutrients bring something unique to the table, meaning you should base your decision off of your plants’ particular needs.
It’s a common thought that organic nutrients offer a better smell and taste for the bud produced. This thought stems from the fact that composted soil, amended with nutrients that come from natural sources, becomes a living soil that often gets pegged as the source for a bold taste and smell in the cannabis buds. It’s important to note, however, that simply using organic liquid nutrients isn’t likely to yield the same results. Organic nutrients aren’t an ideal option for cannabis grown hydroponically because it can lead to unwanted growth in your water reservoir.
Chemical nutrients help to increase the potency of the final product, much in the way organic nutrients help to improve the taste and smell. Chemical nutrients are designed to be easily absorbed by the plants, which can result in faster growth. While chemical nutrients can be useful for cannabis grown in soil, it’s the only option for hydroponic cannabis.
What’s the Difference Between the Brands
The first difference you’ll need to watch for when choosing the right brand of nutrients is their rations. Different brands will deem different NPK ratios ideal for each stage in the growing process; they won’t all be the same. For instance, one company may consider the best vegetative option be 10-4-4, while another believes the better one is 9-4-3. The ingredients that make up the rest of the nutrients or fertilizers will also vary from brand to brand, meaning they will provide your plants with different nutrients.
It’s crucial that no matter which brand you decide on, you choose one designed for your particular medium. Nutrients designed for soil-grown cannabis are different than those for hydroponically-grown cannabis. Coco coir is typically considered a variation on hydroponics, but there are nutrients on the market designed specifically for coco coir. It is important, however, that you watch your supplement usage closely and use caution whenever determining doses, as it can be easy to go overboard.
Finding the right nutrients and supplements to help your cannabis crops thrive can seem difficult and for newcomers to the growing scene, overwhelming. Determining the right nutrient to use and the proper amount of it to administer can be a risky endeavor as well; if you overfeed your crops, you can cause irreparable damage. We hope that, through this article, we’ve helped you to gain good footing to launch your research for properly feeding your cannabis crops so that they grow and thrive.