Companion plants offer cannabis plants many benefits, such as deterring pests, fixing nitrogen, and preventing erosion. The home grower has a wide range of options, from different varieties of clover to herbs like comfrey and yarrow, to edible vegetables like peas. The best strategy is to use companion plants that serve multiple purposes.
Wade Laughter, who is known for identifying and propagating the high-CBD strain Harlequin, now engages in companion planting in an outdoor farm on the western slope of the Sierra Nevadas. Laughter reckons home growers will benefit by creating a diverse environment in the garden.
“With many different kinds of plants, you have a higher chance of attracting the bugs who are your friends,” Laughter says.
There is one universal: all companion plants should be grown low. Zelig Kronberg, head cultivator at Spring Creek Farm in Northern California, uses companion plants that tend not to grow high very quickly.
“We use potatoes, South African ground cherries, and squash specifically as indicator plants to read the water levels and nutrients of the soil,” says Kronberg.
Kronberg plants potatoes around the edges of cannabis plants and ground cherries throughout the bed.
“These two plants protect our cannabis from wind and sun, and retain moisture in the soil. When we cut the companion plants, we mulch that material back into the soil. Anything you can do to feed the soil is beneficial,” Kronberg says.
Cannabis Companion Plants Help Manage Pests
Alec Dixon, co-founder of SC Labs in Santa Cruz, CA., sees companion planting as an aspect of integrated pest management.
“Companion plants repel certain bugs and attract others (that eat pests), like ladybugs. They’re great because they allow you to move away from chemicals and micro-dosing. You don’t have to engage in the rotational use of different harmful sprays when you have basil, coriander, and alfalfa deterring aphids and whiteflies,” says Dixon, adding growers should sparsely spread a companion plant like clover through the grid of the canopy and around the perimeters of cannabis beds. “You don’t need much more fertilizer and water. But you give them the same love.”
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Dixon stated he sees companion plants as a “secondary undergrowth” encouraging high terpene content and terpene expression.
Matthew Frigone, owner of Lazy Bee Gardens, located in the Methow Valley of Washington state, noted his favorite companion plant is White Dutch Clover.
“It’s like a living green mulch. It extrudes different enzymes into the roots and traps the microbes so they feed on each other,” said Frigone, who is also experimenting with chamomile. “It’s known as a doctor plant because it helps other plants. We want to see if it will boost simple oil production in the plants around it.”
Plant Companion Seed and Cannabis Seedlings at Same Time
Typically, cultivators plant cannabis seedlings and companion plant seeds at the same time. As the companion plants sprout, they choke out unwanted weeds.
Companion plants can also eliminate the need for fertilizers. Laughter said he uses companion plants to make compost.
“We have a cover crop and build layers of different materials. Cannabis is a grass with roots that run horizontal. It finds the sweet spots. What you want your companion plants to do is make a net full of those sweet spots with a nutrient-rich environment,” says Laughter.
Laughter added growers should cut down and pull out companion plants that grow tall. This allows cannabis plants to have full access to all the nutrients that the companion plants generated.
Jeremy Moberg, owner of CannaSol Farms in Washington state and president of the Washington Sun Growers Industry Association, has a more intense strategy.
“We’re using chrysanthemums, which is where pyrethrins come from. We put them around the edges and the perimeters of the cannabis plants. We will just let them grow unless they become a nuisance,” Moberg says.
Russet Mites and twospotted spider mites can wreak havoc on a cannabis crop and the chrysanthemums serve a dual purpose.
“One thing I am concerned about is that I hope the mums bloom at the same time the cannabis blooms. That will allow us to get the full advantage. Then we hope to harvest the mums and then incorporate them into a compost tea. We’ll spray that on the seedlings,” says Moberg.
Mushrooms Can Act as Companions
Horticulturists who use companion plants are constantly experimenting with new plants and new ways of using them.
Laughter is now working on mushroom inoculations for cannabis.
“Fungus plays a big part in offering plants like cannabis sugars and carbohydrates. You can distribute spores into your soil. When mushrooms pop up in the root zone of cannabis, those tend to be the happiest plants in your garden,” says Laughter.
Dixon has thought of using other cannabis plants as companion plants.
“Maybe take a strain like ACDC and trellis it not more than a foot above the soil. Then put a bunch of clones of ACDC around the base of the main canopy. That way you can generate a ton of CBD for a cannabinoid extract,” Dixon says.
Read also: How to Grow Mushrooms Indoors
Companion Plants Help Cut Out Chemical Use
For many growers, companion plants are the first step on the path away from using chemicals. Those who are starting out may take a while to see results.
“With companion plants, you might see cannabis plants’ overall health increase.
Companion plants tend to help build your soil’s structure and microbiology, reducing the amount of organic input needed. We still don’t have enough side by side comparisons on different companion plants and what they do. One way I have seen companion plants help is by keeping cannabis plants healthy and preserving a plot of soil for future grows,” says Frigone.
Dixon sees it as unnatural for growers to “cart in all these hundreds of yards of soil and spray chemicals on cannabis that have a skull and crossbones on the bottle.” For him, farming is work.
“It’s showing up and doing the same thing every day. The more you really dive deep into companion planting, the more it starts to make you a real farmer. It helps you team up with all these other superhero plants. Real farming isn’t harvesting a monocrop and then letting the land die. Cultivation takes work and investment in many plants, not just cannabis, and putting all of that back into the land,” says Dixon.