Malibu Compost mainly sold to nurseries, organic vegetable farmers and backyard gardeners until a few years ago, when the small business started by two surfing buddies began getting calls from farmers in Mendocino County.

Co-founder Randy Ritchie drove to Willits and met an old hippie standing near a truck parked away from the main highway. “Can we get a couple truckloads of that?” he asked.

“We were like, what are you guys doing?” Ritchie remembers asking the man.

With the sale, the seven-year-old business had entered the medical marijuana industry.

“We never ever talked about cannabis,” Ritchie explained. “We didn’t go after it. It came after us. Now it has become a huge part of our business.”

There are an estimated 50,000 farms — mostly in Northern California — growing cannabis used for medicine and sold to customers suffering from glaucoma to cancer to anxiety. Now, with the passage of Proposition 64, Ritchie and his partner, Colum Riley, 43, hope to sell their high-grade, cow manure-based compost to growers in the recreational market as well.

At a national compost conference in late January at the Bonaventure Hotel in Los Angeles, the partners advised about 300 growers, composters and farmers to jump into the $7.2 billion marijuana business that experts predict will reach $22 billion nationwide by 2020. Compost companies can make a killing, they said, by selling to growers who want to produce a “cleaner” product free of pesticides.

“If you are in the compost industry, you need to be actively lobbying for outdoor organic cannabis cultivation. That is the market for composting,” Ritchie told the audience.

The cannabis rush

In a market where many growers are still in the closet, Riley and Ritchie’s Malibu Compost spread to cannabis growers by word of mouth to the point where sales to marijuana growers represents 35 percent of their business. Sales of the “bio dynamic” compost, as well as compost teas and other soil amendments have reached $1 million annually, Riley said.

A customer who owns a nursery in Laguna Beach shipped some bags to a friend in Oregon, where marijuana is legal. The word spread to Laytonville, a small town in Mendicino County, where marijuana growers started using it to grow healthier plants and non-contaminated buds, Riley said.

“That one man is responsible for a massive spike” in Malibu Compost sales, Riley said. “We haven’t been able to keep up with demand in the last two years.”

While Riley predicts a windfall for sellers of compost to marijuana growers, others don’t predict a gold rush.

“The suggestion that this is an emerging growth opportunity is probably untrue,” said Hezekiah Allen, executive director of the California Growers Association, which represents more than 1,000 pot growers. “I would not advise the compost industry that there is some huge growth opportunity.”

Instead, state regulations being drafted may actually reduce marijuana output, because California will have to reduce production of medicinal and recreational cannabis starting next year by 40 percent, Allen said. President Donald Trump could lean on California to keep its production in-state. If exports increase, growers could run into foul territory since marijuana is not legally recognized by the federal government.

Most of the growth in medical marijuana in California took place between 2006 and 2012, he said. When the Bureau of Medical Cannabis Regulation releases a regulatory framework next month for a 45-day review period, new rules could end up restricting exports, he said.

Can compost replace pesticides?

Malibu Compost and a growing number of farms say growing marijuana outdoors, in soil, instead of inside a warehouse using hydroponics is better for the product and the environment. Indoors, growers use bottles of fertilizer, as well as pesticides and herbicides, Riley said, contaminating the product and harming the environment.

In-soil cultivation marries with composting, creating a more natural method and a cleaner product, he said.

Ritchie said when he first started selling compost to marijuana growers, some told him they would replace their soil every year. “We started telling guys, why don’t you start revitalizing your soil?” he said. One grower saved $15,000 by reusing the soil. “That helped us become a part of that community quicker,” Ritchie said.

Compost sellers want to carve out a niche market of “organic” marijuana, much like vegetables grown without pesticides and meat from cows raised without hormones.

Some stores, such as Whole Foods, focus on organic products. While there is no such designation for marijuana in California yet, dispensaries are already labeling buds as “sun grown” and “outdoor bio-grown” to portray organic or pesticide-free without printing the word on the label.

“Our customer base will grow as people are willing to pay more for quality — especially when you consider the secondary market for oils, tinctures and edibles,” Riley said.

When these specialized marijuana products are made, THC, the main ingredient that produces a high, is super concentrated, as are the amounts of harmful pesticides. In Colorado recently, marijuana concentrates were taken off the shelves after being found to contain high traces of pesticides that pose a risk to the consumer.

The state Bureau of Medical Cannabis Regulation is aware of the pesticide issue and is drafting regulations that most likely will allow only trace amounts of chemicals. “Part of what we are looking at is we want people to have safe medicine,” said Alex Traverso, spokesman for the new state office. They are working with the California Department of Pesticide Regulations to establish maximum levels.

Consumers will demand better

Nick Boomer, owner of BoomsPharm in Santa Ana, works with other growers to ensure high-quality marijuana through genetics and testing. He owns three acres in Riverside where he grows marijuana. He would not disclose the location and would not allow our photographer to visit, saying it is illegal for non-members of the cooperative to set foot on the land.

Boomer, who spoke at the conference, said he’s very concerned about pesticides in medical marijuana, since he is a medical marijuana user himself. BoomsPharm marijuana products, sold at a licensed dispensary in Santa Ana, are tested for 300 different trace chemicals, he said.

A plot of 25 medical marijuana plants grows in Mendocino County in 2010. The farm needs to show legal paper work for each patient receiving marijuana from the medical grow. (Dan Rosenstrauch/Staff)

“If you have a compromised immune system, or even if you are a healthy individual, you don’t want to be dosing yourself with a pesticide that has been concentrated,” Boomer said.

He said many growers use bottles of pesticides, sprays and harsh fertilizers, leaving chemical residues that do not rinse off the plant.

For example, an oil from plants sprayed with pesticides and herbicides may not contain THC but rather CBD, a non-psychoactive compound which has shown promise in treating skin cancer and other illnesses. (In that case,) “you’d be rubbing pesticides all over yourself,” Boomer said.

The concern about pesticides harming users will heighten in 2018, when recreational marijuana is sold as edibles, such as cookies and brownies, and tinctures applied as drops under the tongue as an alternative to smoking.

Why has the demand for “organic” marijuana suddenly become popular?

With more states adopting recreational use laws and new kinds of marijuana products showing up on shelves, the industry has been placed under a microscope, literally. It’s similar to consumer cries for organic and non-GMO (genetically modified organism) foods, Boomer said.

“People are questioning what is in their water, what is in their food and now, what is in their cannabis,” Boomer said.

Riley believes growers should switch to natural compost products that use worms and soil amendments such as biochar, then sell the end product as cleaner, high-end marijuana for a higher profit.

“It is the same as people who go to the farmers’ markets and ask: ‘Is this locally grown?’ Riley said.