Companion planting is a gardening approach where different plant species are grown together to enhance mutual health and productivity. This practice creates a harmonious garden ecosystem. By strategically placing various plants in proximity, growers can foster a more resilient environment, leading to healthier crops.
Why Use Companion Plants
Companion planting offers several advantages for marijuana cultivation. This method helps create a natural defense system around the primary crop.
Certain plants effectively deter harmful insects. These companion plants often release specific aromas or compounds that pests find unappealing, discouraging them from damaging marijuana plants. This natural pest control reduces reliance on chemical interventions, promoting a more organic growing environment.
Other companion plants attract beneficial insects, such as pollinators or predatory species. These helpful insects prey on common marijuana pests, helping to keep their populations in check.
Some companion plants improve soil quality and nutrient availability. Certain species fix nitrogen from the atmosphere into the soil, while others have deep root systems that draw up nutrients from deeper layers, making them accessible to shallower-rooted marijuana plants. Ground cover plants can also suppress unwanted weeds, reducing competition for water and nutrients.
Companion plants offer physical benefits, such as camouflage and protection. Taller, bushier plants can obscure marijuana plants from view, useful for outdoor growers. They may also provide physical barriers against strong winds or offer partial shade during intense sunlight, protecting more delicate marijuana plants.
Beneficial Companion Plants
Incorporating specific companion plants enhances the health and vigor of marijuana crops. They address various needs, from pest management to soil enrichment, each offering unique contributions to the garden ecosystem.
Pest Deterrents
Marigolds deter nematodes and other general pests. These vibrant flowers release chemicals from their roots that repel harmful organisms, creating a protective barrier around cannabis plants. Basil, with its sweet and pungent scent, helps repel aphids, flies, and mosquitoes. Dill is effective against spider mites, aphids, and caterpillars. Mint, a general pest deterrent, requires careful management due to its invasive growth habit.
Attracting Beneficial Insects
Dill attracts beneficial insects like ladybugs, parasitic wasps, and hoverflies, which are natural predators of common cannabis pests such as aphids and thrips. Yarrow, with its flat-topped flower clusters, draws in hoverflies and ladybugs, aiding in pest control. Clover, particularly white clover, attracts beneficial insects.
Soil Health and Nutrients
Clover, including microclover, Dutch white, red, and crimson varieties, is a valuable nitrogen-fixing plant that enriches the soil. It also acts as a living mulch, suppressing weeds and retaining soil moisture. Alfalfa is another effective nitrogen-fixing legume with deep roots that improve soil structure and water penetration. Comfrey, a dynamic accumulator, draws nutrients from deep within the soil, making them available to other plants when its leaves decompose.
Physical Protection and Camouflage
Borage, with its nectar-rich blue flowers, offers physical protection. Sunflowers serve as tall, sturdy plants that provide shade, act as windbreaks, and offer camouflage for marijuana plants.
Flavor and Aroma Enhancement
Chamomile enhances essential oil production in nearby plants, which may contribute to the terpene profile of cannabis. Basil promotes terpene growth in cannabis.
Plants to Avoid
While many plants offer benefits as companions, some can negatively impact marijuana growth and should be avoided. Certain species compete aggressively for essential resources, hindering cannabis development. These include plants with extensive, shallow root systems that directly compete for water and nutrients in the topsoil.
Some plants attract harmful pests or diseases that can easily spread to marijuana crops. Introducing such plants can inadvertently turn a companion planting effort into a source of infestation. For instance, plants known hosts for spider mites or aphids should be kept at a distance.
Some plants exhibit allelopathic effects, releasing chemicals into the soil that inhibit the growth of nearby plants. Black walnut is a notable example, producing juglone, a compound toxic to many plant species, including cannabis. Aggressive spreading plants, like certain mint varieties if not contained, can quickly outcompete and overwhelm marijuana plants for space and resources.
Tips for Successful Companion Planting
Implementing companion planting effectively requires thoughtful planning and ongoing observation to maximize benefits for marijuana plants. Careful consideration of plant needs and interactions is essential.
Spacing and placement are crucial. Plants with similar light and water requirements should be grouped, but adequate space must be maintained to prevent overcrowding and competition. For ground cover plants, 6-8 inches spacing is effective for weed suppression. Mid-height companions might need 12-18 inches from cannabis plants, while tall barrier species often require 3-5 feet for proper airflow and light penetration.
Ensuring soil compatibility is important, as companion plants should thrive in similar soil conditions as marijuana, which prefers well-drained, nutrient-rich soil. Matching watering needs prevents over- or under-watering. Regular monitoring of plant interactions allows growers to observe performance and make adjustments.
Companion planting integrates well with organic gardening practices, reducing the need for synthetic pesticides and fertilizers. This holistic approach supports a healthier soil microbiome and a more resilient garden ecosystem. For those new to companion planting, starting with a few well-researched combinations on a smaller scale provides valuable experience before expanding.