Editor’s Note: David Holmes, CEO and founder of Clade9, is featured on the cover of the March 2022 issue of Cannabis Business Times. Read more about how he started his journey in the cannabis industry here. Details about his cultivation vision, priorities and post-harvest processes are below. 

Over the years, David Holmes, CEO and co-founder of Los Angeles-based Clade9, has grown plants in everything from deep water culture to rock wool.

Holmes was growing in deep water culture when he first met famed photographer and cannabis author Mel Frank, whose books Holmes had read when he was first learning to grow two decades ago. Frank had been looking for a grower with a precise setup to help one of his colleagues conduct an “experiment … on the effect of UVB ultraviolet on THC production, whether it enhanced it or did anything,” Frank recalls.

“Deep water is pretty sensitive,” Frank says. “A lot of things that can go wrong with it. Equipment failures, microbial problems, stuff like that, because basically you’re just growing a plant in pure water. It needs oxygen being bubbled in. Temperature has to be monitored very closely.”

Frank recalls thinking immediately, “Well, this guy’s got this together. If he’s able to operate this and bring a crop through this, he knows what he is doing.”

Today Holmes grows in rockwool at Virtue’s Las Vegas facility and at his L.A. operation.

“I like rockwool because it’s really clean …, it’s lower labor,” he says, whereas if you’re growing in soil, for example, “it’s really messy, it’s everywhere. And then there’s a lot of labor and potting, and it’s heavier.”

Plus, as a self-described “precision cultivator,” Holmes says, “I just like the fact that it starts with basically a zero cation exchange capacity, so you can essentially set your nutrient solution precisely from the start.”

 “How many plants do you put per square foot? If you reduce it, does it change your flower size? I mean, those are the things we really have to dig into in California just because it’s so competitive. You’re like, ‘Oh shit, we got to make sure everything is on point.’ Even average flower size. That’s really important.” — David Holmes, CEO and founder, Clade9

Cleanliness, precision, control, continual learning and, of course, math are keys to Holmes’ vision for his operation, from genetic development to cultivation and post-harvest.

His grow rooms resemble operating rooms, with immaculate white walls and floors almost glistening under the HPS and LED lights. All cultivation team members (and all visitors) dress head to toe in scrubs, part of the clean room environment that is critical to the company’s integrated pest management strategy, says Holmes.

“I’ve seen just about everything [as far as pests and diseases] over the last 20 years, which taught me the importance of quarantine. Starting with clean plants is probably the most important thing you can do to keep your garden clean in the early stages. To keep it clean over time, it will take a combination of a preventative IPM program and good cultural practices,” he says.   

Controlling the environment is also essential, and the team regularly collects and analyzes crucial data points including “temperature, humidity, VPD [vapor pressure deficit], light intensity, nutrient solution, … soil EC [electrical conductivity], CO2,” Holmes says.

But as other growers can attest, 100% precise control over a living organism is far from easy. 

“Working with controlled environments gives us precise controls over the environmental factors going into cultivating these plants, but the fact that you’re manipulating a living thing still makes it feel like more art than science,” says Clade9 Cultivation Manager Brandan Nakamoto, whose background includes a B.S. in agriculture and 20 years in agricultural work on crops ranging from bananas to corn. “It doesn’t take much deviation from the optimal conditions to change the final product.”

The intersection of art and science could be compared to a never-ending math equation that Holmes and his team are eager to continue trying to solve through ongoing experimentation.

Right now, that process has taken them “deep into irrigation.” (The facility is equipped with automated irrigation with drip stake emitters.) “We’re looking at how the irrigation is changing the moisture level in the ‘soil’ over the feeding period of the day,” Holmes explains. “If you irrigate … six times versus 12 times or 18 times, and you watch the moisture level and the EC … with different strategies, how does that affect growth response? … We still have a lot of work to do, but we’ve noticed some changes based on changes we’ve made in the irrigation techniques.”

Another area the team is exploring is plant density. “How many plants do you put per square foot? If you reduce it, does it change your flower size? I mean, those are the things we really have to dig into in California just because it’s so competitive,” Holmes says. “You’re like, ‘Oh shit, we got to make sure everything is on point.’ Even average flower size. That’s really important.”

Post-Harvest Precision

Control is also key in post-harvest. “There are several factors we focus on … but all are geared toward maintaining our high safety and quality standards,” says Gustavo Reyes, Clade9’s director of operations. “Our process control is outlined at every step through standard operating procedures, and our team is properly trained,” he says, from trimming through packaging, as well as in operational areas such as inventory management, efficiencies and cost reduction.

Part of the post-harvest process control, says Reyes, is “when the plant is drying, we want to maintain 49 to 51% humidity and temperatures between 68 and 64 degrees, starting at the higher range and dropping throughout the days. We also maintain the ‘lights off’ to help ensure we don’t degrade the color. After that, we try to maintain our process rooms with temperatures in the low 70 degrees and exposed as little to the light as possible. We also ensure the product remains sealed throughout the process to help maintain the freshness.”

In the competitive California market, moisture level, among many other quality factors, is critical. Dry bud won’t fly off the shelves in the Golden State. Clade9’s target moisture level, says Reyes, is “.50 aw (water activity) in all flower products.”

And, as in the cultivation rooms, data is front and center. “Our data analysis at every stage gives us a great understanding of areas we are effective in as well as helping us identify areas of opportunities,” he says.