Many cannabis gardeners focus all their attention on the flowering stage of growth, where the magic happens in terms of cannabinoid and terpene production. However, the seedling/cloning, the early vegetative, and the vegetative growth stages are where the basis for success is set. After all, a strong foundation is key to a high-yielding garden. Therefore, the vegetative stages of cannabis growth are the foundations for a higher return on investment. In fact, the entire growing process up to the flowering stage can be viewed as laying the foundation for a successful cannabis garden. This foundation can be broken down into three parts, each with its own unique nutritional needs: the seedling/cloning stage, the early vegetative stage, and the vegetative growth stage.
A freshly cut clone or a freshly germinated seedling have very similar nutrient requirements: none. One of the largest blunders a novice cannabis grower can make is feeding nutrients to freshly cut clones or newly emerged seedlings. As seedlings first emerge from the medium, they get all their necessary nutrition from within the seed itself (stored there for the germination process).
Generally, a seedling will not require additional nutrition until it develops its first set of true leaves. During the initial germination process, all a seedling needs is a well-aerated medium and the proper atmospheric conditions (temperature and humidity). A seedling heat mat combined with a thermostat and a humidity dome are all a cannabis grower really needs to get his or her seedlings germinated and off to a good start.
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Like newly germinated seedlings, freshly cut clones do not require nutrients. In fact, giving rootless clones nutrients is pointless considering they do not have the root structure to absorb those nutrients. Instead of providing nutrients, cannabis growers should provide fresh cuttings with a rooting hormone or a product designed to stimulate root development. Vitamin B-1 is also commonly given to cuttings to help alleviate stress and provide a smooth transition as the clone goes from being part of a plant to becoming its own individual plant. One common misunderstanding is that the cloning medium should be inoculated with fertilizers so when the new roots emerge, they have instant access to vital nutrients. Although a small amount of low-nitrogen fertilization can be helpful to rooted clones, high nitrogen fertilizers can hinder the plant hormones that would otherwise help produce new roots. Excess salts in the medium where new roots are developing can also make it harder for fresh roots to absorb the water they need to survive. The best way to provide nutrition to clones is not to do it; that is, until a healthy number of roots have appeared. Once there is an established root system, the plants can transition to the early vegetative stage.
Early Vegetative Stage
The early vegetative stage for cannabis plants refers to the stage right after the first set of true leaveshave emerged (with seedlings) or a healthy root system has developed (with clones). Essentially, the early vegetative stage is the stage between the seedling/clone stage and the full-on vegetative growth stage. Another common mistake made by new cannabis growers skipping the early vegetative stage completely and treating young vegetative plants the same as more mature vegetative plants. Using a high-nitrogen vegetative fertilizer during this stage can impede the development of a strong root structure. During the early vegetative stage, the focus should still be on strong root development. Developing a healthy and robust root mass is one of the most important foundational aspects leading to large cannabis flowers. Stimulating the root mass during this stage will help increase the plant’s overall structural integrity.
A strong structural integrity is needed for vigorous vegetative growth and, eventually, the development of large buds. Specific root development products can be integrated into the feeding regimen during this stage of growth to further enhance root development.
Formulas rich in nitrogen should be avoided, including most vegetative-specific fertilizers. A blooming fertilizer used at a diluted strength is one effective way to feed early vegetative plants. Generally speaking, a blooming fertilizer will still contain all the essential elements, but with a ratio of N-P-K that is more suitable for root development during the early vegetative stage (less nitrogen). Many enzyme and/or beneficial microorganism additives specific to root health and development can and should also be incorporated during this stage of growth. It’s important to keep in mind that plants in this stage are young and can still be very sensitive to any drastic change (nutrient or environmental). As in the clone/seedling stage, Vitamin B-1 can be supplemented during the early vegetative growth stage to reduce the likelihood of any stress.
Vegetative Growth Stage
After the early vegetative plants have bulked up their root masses, they can be transitioned to a full-out vegetative fertilizer regimen. Vegetative-specific fertilizers, a.k.a. “grow” fertilizers, are solutions containing all of the essential micro- and macronutrients needed for healthy plant development. Although both micro- and macronutrients are necessary for healthy plant growth, macronutrients are defined as those used in higher concentrations by the plants; whereas micronutrients are defined as those used in lower quantities.
The essential elements for cannabis plants that fall into the macronutrient category (in order from highest to lowest quantities used) are: nitrogen, potassium, calcium, phosphorus, magnesium, and sulfur. The essential nutrients that fall into the micronutrient category (in order from highest to lowest quantity used) are: chlorine, iron, boron, manganese, zinc, copper, molybdenum, and nickel.
Read also: Essential Nutrients for Growing Cannabis
A high-quality, vegetative-specific fertilizer will contain all the essential elements. A “grow” fertilizer with a guaranteed analysis that mirrors the order from the highest to lowest quantity of essential elements used by the plants will generally perform the best.
Nitrogen is the element most responsible for green, lush growth and a good vegetative fertilizer will have nitrogen as the most plentiful nutrient. However, providing cannabis plants with a balanced nutrition regimen is imperative to building the foundation for a successful flowering stage. In addition to the essential elements, a solid vegetative feeding regimen will include elements that are considered beneficial. Although not deemed essential for plant growth, silicon, sodium, cobalt, and selenium have all shown to be influential in plant development and can be used to further enhance vegetative growth.
Other Beneficial Additives for Vegetative Growth
In addition to a complete vegetative fertilizer regimen with essential and beneficial elements, some growers give their vegetative gardens another boost with other helpful additives. Kelp, for example, contains powerful plant hormones that can enhance vegetative growth rates. Amino acid formulas are also popular for increasing growth rate during the vegetative stage. Amino acids are the building blocks of all proteins and play a major role in the composition of cells. Carbohydrate formulas (though primarily used in the flowering stage) can also provide benefits in the vegetative stage. Carbohydrate formulas fed to the roots can feed vital microorganisms, which, in turn, break down organic matter and feed the plants. Humic and fulvic acids are more beneficial additives used by cannabis growers. They work as chelators. More specifically, they combine particular minerals into organic compounds that can be readily absorbed by the plants. Humic and fulvic acids have the ability to increase a soil’s water holding capacity and can also restrict toxins in the soil, thus reducing the amount of harmful substances that can reach the plant’s roots.
Final Thoughts on Pre-bloom Cannabis Feeding
The clone/seedling stage, the early vegetative stage, and the vegetative growth stage should all be treated as separate entities when it comes to nutrition. Although high-nitrogen fertilizers are associated with the vegetative stage in a cannabis garden, they should only be used after the young vegetative plants have established a healthy root structure. When it comes right down to it, the reason the vegetative stage is broken down into three stages is to provide the plants with proper nutrition, while creating a strong and healthy foundation for the flowering stage of growth.
Cannabis cultivators that tailor their feeding regimens to best match the plant’s particular stage of growth will be rewarded with stronger plants and a healthy root structure. Cannabis plants that have been fed properly during the three stages of vegetative growth will be structurally and metabolically ready for flowering and prepared to grow up to their fullest potential.