Ask a cannabis cultivator or grower about the advice they have for an aspiring grower, and many of them answer something like, “First, grow a tomato plant, and then come back so we can talk.” They say that if someone can’t grow a tomato plant, they should pause on growing cannabis. In a 2016 article written by Christopher Gallagher for DGO, he states: “Tomatoes and cannabis also grow in remarkably similar conditions — similar soil, lighting, and care will yield similar-quality finished products.”
Cannabis is known to grow in all types of climates, mediums, and spaces; it is a magical, resilient plant. And while cannabis as a whole is medicine; medical-grade cannabis is different from recreational or adult use-grown cannabis. Just about every cultivator agrees that cannabis cultivation should be extremely researched, and that cultivators, no matter how long they have been growing, should consistently stay up to date by reading about new research, new science, and new concepts.
Growing cannabis, like many other plants, requires more than just light and water; soil and nutrients are crucial to plant growth. Plants and humans aren’t that different. After all, when a human body is lacking nutrients, it doesn’t feel and perform at its best. As the same goes for plants, it goes for cannabis as well.
To get insight on nutrients and soil for growing healthy cannabis plants, I interviewed Anthony Domangue, a cannabis cultivator based out of Missouri. Anthony cultivates medical grade-cannabis and has experience growing indoor and hydroponics. In addition to cannabis, Anthony grows herbs and vegetables in outdoor soil, indoor, and hydroponic settings. I also interviewed Daniel Price, a cultivator of cannabis and various plants and vegetables, with experience in the Midwest and Colorado regions.
In your opinion, what’s the best growing medium for cannabis for each region?
Daniel: “Personally, I love growing outdoors, under the sun, in rich beds of native soil that I’ve amended with responsibly sourced minerals and organic matter, cover crops, and mulch. The less tillage, the better. The media, in this case, would best be described as a dynamic biological system, “the soil food web,” as Elaine Ingham coined it. It also happens to be the most economical and environmentally-friendly way to grow.
Although I have respect for all other types of growers, I prefer outdoor, biotic, living systems and styles, as they are applicable in all regions of our country, as well as North and South America more generally.”
What are the most important nutrients for the cannabis plant, in each stage of growth?
Anthony: “The most important nutrients from seedling and clone through the end of vegetative growth and vegetative cycle are:
- nitrogen, which drives plant growth by helping the plant capture sunlight energy via photosynthesis, needed for healthy leaf growth, and development.
- phosphorus, which stimulates root development and increases the stalk and stem strength.
- zinc, which is directly involved in the creation of chlorophyll.
- and chlorophyll, which is directly involved in the creation of auxin (a key plant hormone which is involved in regulating plant growth) and other growth hormones.
The most important nutrients during the flowering/bloom phase are:
- potassium and phosphorus. Potassium helps plants move water, nutrients, and carbohydrates within plant tissue; it also activates multiple enzymes in numerous metabolic processes including protein/starch synthesis and energy generation. Additionally, potassium plays an important role in modulating the intracellular environment by maintaining ionic tone, buffering pH, and promoting favorable electrochemical conditions at reaction sites. Phosphorus converts sun energy into food, fiber, and oil; it sets strong buds.”
Daniel: “The three main macronutrients for plant growth are nitrogen, phosphorus, and potassium, typically referred to as NPK. The way I learned it is that nitrogen equals leaf and stem growth, phosphorus equals fruiting and flowering, and potassium equals plant metabolism. Other elements are sulfur, calcium, and magnesium — also essential for flowering and fruiting. “Trace minerals” refer to plant nutrients needed in small amounts (aka micronutrients), which include iron, boron, chlorine, manganese, zinc, copper, molybdenum, nickel, and others.”
I’ve heard the term “super soil.” Are you familiar with that term, and if so, what does that mean?
Anthony: “Yes, super soil is another term for living soil. This means that the soil is full of beneficial microbes that work together to break down organic matter and subsequently provide plants with all the nutrients needed for successful growth. It’s similar to probiotics or good bacteria in humans. It’s just providing that living, beneficial ecosystem to support healthy growth.”
Daniel: “I am familiar with this term. Super soil generally refers to custom, homemade soil mixes that growers make using diverse and nutrient-dense ingredients. Cannabis is a “heavy feeder” like other vegetables and likes to grow in heavily amended, nutrient-rich soils.
If you’re just starting out, follow the “30-30-30” recipe of 30% peat (supplement coco if that’s your jam), 30% perlite/pumice/vermiculite or other aerating/drainage element, and 30% compost. To make it “super,” add rock dust and soil amendments like animal and plant meals (responsibly sourced), or save yourself the time and purchase a premade potting mix that has everything your plant needs from seed to harvest.
Visit your local grow store, and see what they’re sourcing. If they don’t have the soil you’re looking for, then let the store manager know about the product, and they’ll order it for you.”
What’s the most important piece of advice for a beginner to cannabis cultivation regarding nutrients and soil media?
Anthony: Study the basics on macronutrients and micronutrients needed to grow successful plants. It’s the foundation of being a successful grower, in my opinion. For soil media, know how well your media drains water and plan your irrigation strategy around that. Coco coir and rockwool cubes will dry out much quicker than certain soil- and peat moss-based blends, for example.
Daniel: “My advice for the beginner grower: Don’t overthink it! Read about what plants need to grow and watch videos on modern horticulture topics like CEA (controlled environment agriculture) and regenerative agriculture. Also, talk to your neighborhood grow store. They’ll break down the three basic types of media for you: soil, coco, or rockwool. Just keep in mind that if you go with coco or rockwool, you have to also purchase nutrients in liquid, powder, or chelated form, whereas high-quality soil and compost teas will have everything your plant needs to grow healthy and strong.”
In your opinion, do laws and regulations keep the industry from utilizing the best nutrients for cannabis. Why or why not?
Anthony: As far as I’m aware, no. All the reading I’ve done says states are pretty free in terms of regulating the nutrients commercial cultivators use. Cannabis can’t be labeled organic, though, because it’s federally illegal and can’t be tested under the USDA.
Daniel: “In my opinion, no. There are plenty of options for media and nutrients for all types of growers, but just be sure to do your homework. I recommend that cannabis growers become familiar with and follow 25B as well as any guidance or regulations in their home state’s Department of Agriculture.”
Veronica Castillo is a resident of the road, a nomad, exploring all thing’s cannabis and hemp in the United States and very soon, abroad. Before cannabis, Veronica worked in insurance and human resources. You can follow her journey on IG @v2_traveling_veg_canna_writer.