Ask a Cultivator: Vee’s New Column in Grow Magazine

Recently I wrote a piece for Grow Magazine: Ask a Cultivator, with a focus on grow media and nutrients. My editor liked the idea so much that together we agreed to launch the column. The piece that started this is below (it was originally written by me- Veronica Castillo for the Spring/Summer issue of Grow Magazine), and going forward, readers of Grow Magazine will hear from growers from all over, about various cannabis and hemp cultivation topics. The column will be a Q & A with questions and answers covering all areas of cultivation. 

Check out the piece below and stay tuned for more in Grow Magazine.

Photo by Author- Flower grown by Wunderkind Extracts

Ask a cannabis cultivator/grower about the advice they have for an aspiring cannabis grower, and many of them answer: “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 an 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/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 on reading about new research, new science, 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; when a human body is lacking nutrients, it doesn’t feel and perform at its best, same goes for plants, same goes for cannabis.

To get insight on nutrients and soil for growing healthy cannabis plants, I interviewed a cannabis cultivator based out of Missouri: Anthony Domangue. Anthony cultivates high 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: west/ east/ north/south?

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. 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/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/clone through the end of vegetative growth/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. Chlorophyll which is directly involved in the creation of auxins and 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.”

Photo credit: Drip Works

Daniel: “The 3 main macronutrients for plant growth are Nitrogen, Phosphorus, and Potassium typically referred to as NPK. The way I learned it: Nitrogen = leaf and stem growth, Phosphorous = fruiting and flowering, and Potassium = plant metabolism. Other elements are: Sulphur, 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. 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 pre-made 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 rock wool, 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 law/regulations keep the industry from utilizing the best nutrients for cannabis; why/ 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.”

This article was originally written by Veronica Castillo for the Spring/Summer issue of Grow Magazine and has been repurposed slightly for the Vee, Traveling Vegan Cannabis Writer blog.