Professional golf and cannabis cultivation might not seem like they belong on the same resume, but Marshall Davis has had storied careers in both professions. He talked to us about his path from golf courses to his current cannabis farm, Up the Hill Farms, where he’s had overwhelmingly positive results using PittMoss® in his latest cannabis cultivation cycle.
Marshall became a golf professional in 1987. He began growing cannabis as a closet cultivator while working at golf courses in North and South Carolina. He learned about growing cannabis indoors by reading magazines like High Times and The Cannabis Bible.
In 1996, Marshall became a full-fledged PGA member. He was invited to join the Canadian PGA tour in 2004. After playing on the Canadian tour for a year, Marshall retired from professional golf. He then returned to his home state of California, where he was invited by friends to do indoor cannabis grows with them in garages.
Beginning in 2000, Marshall cultivated medical marijuana in warehouses for a commercial project. After continuously working eight-week harvest cycles for ten years, Marshall relocated to Ukiah, where he did his first outdoor grow in 2011.
Marshall specializes in a high-grade strain called PK or Pure Kush, which is a difficult strain to grow indoors. “Most of the outdoor strains that we grow in the northern part of California are mid-grade strain because they’re easier,” Marshall said. “They take what the elements throw at them a little better than some higher-grade strains.”
For his 2018 grow, Marshall grew a hybrid variation of PK called OG Bomb. He started his grow on July 15th, growing 520 plants in five-gallon pots. Growers in Ukiah are permitted to use 2,500 square feet to grow cannabis, but Marshall only used 1,100 square feet.
In choosing a growing medium for cannabis, Marshall looks for “something that won’t dry out or shrink” in order to conserve water. His medium was a mix of 30 percent PittMoss®, 30 percent Coco Coir, and 40 percent fermented bark medium. He also mulched each pot with PittMoss®.
Marshall also created his own fertilization ratio of 12-22-36, or 12 percent nitrogen, 22 percent phosphorus, and 36 percent potassium. “My experience with cannabis is that potassium is extremely important for finishing the flower off,” said Marshall. “It seems to firm up the buds a lot better than if you were using a high nitrogen feed.”
Marshall grows his cannabis plants vegetatively through the spring until early fall when daylight hours decrease. He refers to this method as “sea of green growing”, which involves growing a large number of plants closely together. He prunes top buds in the canopy only, resulting in smaller, more controllable plants.
Though plants naturally begin to autoflower when daylight decreases, Marshall adds supplemental light throughout his garden for six additional hours to keep the cannabis plants in vegetative growth. He repeats this process until mid-August, when he reduces the supplemental light. The plants flower until the buds are ready to harvest in mid-October.
Marshall was introduced to PittMoss® during his 2017 cultivation cycle after he had already planted all 43 of his cannabis crops in 60-gallon Smart Pots. He used PittMoss® only as a mulch, and he used approximately 75,000 gallons of water between the end of May and the beginning of October. In 2016, without incorporating any PittMoss® into his pots, he used 85,000 gallons.
In 2018, by using PittMoss® throughout his growing medium and also as mulch, Marshall dramatically reduced his water usage. “My total count was 10,600 gallons of water,” he said. “Depending on the weather, I’m sometimes going two days without watering. In a five gallon pot, that’s pretty crazy.”
PittMoss® also significantly expedited Marshall’s cannabis cultivation and harvesting cycle. In 2017, the entire process required approximately nine months of work. In 2018, it took less than six.
When Marshall planted his cannabis crops on July 15th, they were only one and a half to two inches tall without any visible roots. The average height of his plants when he began harvesting on October 15th was 60 inches.
“The roots just shot through the pots and went into the ground,” he said. “I had to tear the pots from the ground when I was harvesting. People are definitely raising their eyebrows when I tell them what the deal is [with PittMoss®].”
Marshall’s customers were impressed with the appearance of his cannabis crops this cultivation cycle. “People commented on the diameter,” he said. “They couldn’t believe how strong and woody they were. … The second and third branches from the main stem were really hard. Usually they’re thinner and don’t hold up the flowers well.”
Marshall’s final yield was 195 pounds total of usable product. He packaged the best of his buds, which weighed 70 flower pounds total. His dedication to growing the best possible cannabis crop paid off, and he sold his entire harvest to a select customer base.
Despite his success in the industry, Marshall stresses the challenges and expenses associated with cannabis cultivation. Cultivators have to deal with strict testing of their product for metals and other contaminants that can show up in the final buds. Although the industry used to test soil for contaminants in parts per million, it now tests in parts per billion and is preparing to test in parts per trillion.
Though Marshall tests his water and soil frequently, growing with PittMoss® blended into his medium helps to minimize how often he has to test his soil for contaminants. PittMoss® passed Redfield Proctor’s pesticide screening battery and received the “Suitable for Cannabis Growth” certification, which confirms that it is a pesticide-free growing medium.
Marshall plans to use PittMoss® again for his next cultivation cycle in the same ratio with Coco Coir and fermented bark medium but will increase the container size from five gallons to seven. He also intends to fertigate extensively instead of hand watering, which proved to be too tedious of a process.
According to Marshall, "The product [buds] in the bag, as far as the results, was pretty damn good.” When asked if he would recommend PittMoss® to other growers, Marshall said, “I absolutely would. I’m blown away at how it aerifies the soil.”
Reflecting on his career in the cannabis cultivation industry, Marshall said, “In the future, I’d like to be doing cultivation, processing, and manufacturing. That’ll be my endgame.”