Culture

Ask a Farmer: Robert Sutherland discusses cannabinoid quantities and avoiding nutrient burn

Ask a Farmer is a new monthly column from The Cannifornian where California cannabis farmers answer reader-submitted questions about marijuana.

This first column includes responses from Robert Sutherland, 74, who is a founding member of the Humboldt-Mendocino Marijuana Advocacy Project (HUMMAP).

HUMMAP is a membership organization of small organic growers and claims to be the first advocacy group formed in the Emerald Triangle.

Sutherland has a strong background in environmental advocacy and advocates for environmentally-friendly cannabis cultivation practices. He lives near Ettersburg in Humboldt County.

The following answers were compiled by Sutherland with the input of other HUMMAP members.

Q: What type of chemical information would you like to have about your crop? E.g. Cannabinoid quantities through time? Cannabinoid quantities under different growing conditions? Or are you most interested in the cannabinoid quantities at harvest?

A: Marijuana crops differ greatly in their intended use. What works for pain or recreation may not be desirable for some medical conditions.

Many of our growers provide product for cannabinoid extraction processors, who in turn produce CBD oils for pediatric seizure patients. They grow from standardized clones so as to produce a chemically uniform product.

Buyers don’t want to buy just any pot that walks through the door. They want to know in advance what they are getting rather than pay for expensive testing to find out, and so they usually supply the clones themselves.

It is the fad for recreational users to pick buds by color or THC content. These mostly come from unstabilized genetics that are likely to fall down in two or three generations. Until those strains are well stabilized, this is not the way to build a business.

Q: My Cali-Magic Cal-Mag supplement claims that its use reduces the chances of nutrient burn in conjunction with base nutrient formulas. Is this possible?

A: Not having tried this — we believe in organic — I have to rely on my decades-old college training.

This is only going to buffer against burns of being too careless. If you are feeding natural ingredients, you quickly learn how much is too much. The amount of calcium and magnesium needed is very small, and need not be added as specific supplements, in my experience.

What you want to focus on particularly for flowering plants is phosphorus and nitrogen. Either of these can burn marijuana plants. If the Cal-Mag is going to stop that, you are using too much nitrogen and phosphorus, and they will block burning by blocking the uptake of such nutrients — usually not an intelligent strategy.


Questions for future columns can be submitted to askafarmer@thecannifornian.com. Identifying information of the questioner will not be published.

Cannabis farmers interested in answering questions are asked to send an email to askafarmer@thecannifornian.com.