Companion planting is a method of cultivation where various plants are grown together in ways that promote a dynamic, flourishing ecosystem to increase yield and health of both plants and soil. Inter-cropping denotes mixing species of herbs, flowers and other plants together with an original crop of choice. In recent years, the proven benefits of inter-cropping have been rediscovered. Acres and acres of land with just one crop, monoculture, are highly vulnerable to disease, pests, weather extremes and depletion of the soil at a record pace. The vast majority of current commercial cultivators grow Cannabis sativa L., (Cannabis) as a monocultural crop, which often entails the use of toxic pesticides and plant growth boosters to maximise profit. There are virtually zero examples of monoculture in nature and unlike monoculture, sustainable growing practices mimic what is done in nature and seek to recreate it in a controlled setting. Human beings were growing sustainably long before the advent of toxic, soil-depleting industrial agriculture. The corporate-dominated agricultural system is broken.
Plants allowed to grow in symbiosis with other species enjoy all sorts of advantages over monoculture crops. For example, Happyday Farms in Northern California, US, grows 47 different kinds of vegetables alongside their outdoor Cannabis varieties. This maximises space and harvest as much as possible. Companion planting lowers cultivation costs and mitigates risk by providing economic protection, as in the event of a theft or raid, food crops are left untouched and are able to be sold. “Companion planting can seem daunting if you don’t know which plants to use” said Ryan Flint, Mendocino county California soil scientist and permaculturalist at Portal Plants. “Each kind of plant has specific growing conditions and needs”. Understanding what a plant likes or dislikes and appreciating the unique qualities of each cultivar are crucial for inter-cropping. Flint starts his Cannabis seedlings using mycorrhizal fungi inoculation. He observed a dramatic enhancement of the health of Cannabis and other plants. “Mycorrhizal fungi grow into the root cells of your plants and work symbiotically. They feed the plants water and micronutrients. In exchange, the plants then feed the fungi the extra sugars produced from photosynthesis. Avoid plants like cucumbers, melons and squash. Try growing dark leafy greens instead”.
As a general rule, avoid propagating crops in proximity to Cannabis that are vulnerable to the same environmental threats, like powdery mildew and mites. Avoid growing plants with deep roots next to Cannabis. Plants with a shallow root structure do not compete for underground real estate. Cannabis can be a great comrade for other plants in the garden with its deep taproot, good for aerating soil and bringing nutrients closer to the surface. Including Cannabis in a crop rotation may make nutrients more readily available for crops that come afterwards. By planting a diversity of species, biodiversity increases, promoting the overall health of the entire growing environment, whereas monocultures are very fragile systems which degrade and deplete the habitat of all plants. Several different species of flowers are likely to attract more insect species in turn, while further improving the environment for soil microbes. Soil health is key to growing strong, healthy Cannabis. Soil is living matter, occupied by microbial colonies that break down organic matter. When these microbes eventually die, they provide nutrients in turn for reintroduction into the soil ecosystem. Some microbes also help keep nitrogen levels balanced. This explains how plants contribute to soil health and the vitality of the Cannabis plants grown in that soil.
The role of pest control in companion planting can range from attracting beneficial insects, to trapping bad ones. Learning to tolerate minor pest infestations is, however, a must. Pot marigold (Calendula officinalis) and Clover (Trifolium) can both have problems with powdery mildew and the latter can become a trap crop for different types of mites, allowing them to multiply. Green-waste from companion plants can be utilised as a bioavailable nutrient source when properly recycled. Feed it to animals, chop and drop (based on canopy density), make into ferments or layer into compost or vermicompost (worm compost). Management techniques will vary based on specific biogeographic conditions. Companion planting at higher spatial densities increases the habitats available for beneficial insects to flourish but improper management of this polyculture can lead to unintended consequences, such as vectors for pests and disease, which lead to other maintenance costs. When a companion planting system is properly integrated, it provides diverse resources far beyond the scope of what traditional pest management can offer alone. Through mastery of botany, entomology and soil science, one can achieve this biological integration in their environment.
Many times one plant will perform multiple roles. Knowing the relationship of beneficial insects to flowering plants is an important step to proper companion planting. There are quite a few different species available to purchase online if need be. Ladybird beetles (Coccinellidae), Green lacewings (Mallada signata) and Pirate bugs (Orius armatus) are fairly common. Many species perform best within their designated range of specific environmental parameters. Photoperiod, temperature and relative humidity are typically the main factors; it is up to the gardener to perform due diligence and monitor environmental conditions to match them in a ‘regular garden’ or an even more controlled setting (indoor growing). Increasing the availability of flowers is often the single most important strategy for increasing the abundance and diversity of beneficial insects. Like pollinators, such as bees, many insect predators and parasitoids feed on flower nectar or pollen during one or more of their life stages. Some predatory insects also feed on pollen as a supplemental source of protein—often when prey insects are in short supply or to increase eggs they can lay.
By increasing the availability of flowers, the number of, longevity and reproductive potential of beneficial insects is increased. In general, quite a few flowering plants are needed to attract a large volume of beneficial insects. In order to achieve high numbers of beneficial insects, anywhere from 5%-50% of the square footage of the space dedicated will be required. This can be achieved by planting low growing species like Pot marigold (Calendula officinalis) or Clover (Trifolium), for example. Beneficial insects can be prey specific, so some understanding of the pest problem is required along with knowledge of the beneficial insects role. Ladybird beetles (Coccinellidae) are known to eat around 2,500 aphid (family Aphididae) during their lifetime. Green lacewings (Mallada signata) are generalist predators whose larvae feed on soft-bodied arthropods including many aphid (family Aphididae). Pirate bugs (Orius armatus) are excellent generalist predators for thrips (nearly 900 species are currently recognised and described in Australia) and spider mites. Worldwide there are well over 1,200 spider mite species with the most well-known and problematic being the Red or Two-spotted spider mite (Tetranychus urticae). Certain species of predator mites are excellent controls for spider, broad and russet mites.
Adding the right neighbours can be a source of protection for Cannabis. Some herbs secrete certain aromas that can help repel insect pests. These aromas are usually associated with terpenes similar to the ones Cannabis uses for protection. Growers can decide to surround Cannabis with herbs particularly attractive to specific pests instead. If done right, the companions will serve as decoys, distracting harmful pests from fragile Cannabis seedlings by offering a tastier alternative. This is a very eco-friendly pest control technique that uses the power of nature. Lots of anecdotal evidence exists to show certain companion plants will boost or at least alter the terpenes of Cannabis. Basil (Ocimum basilicum) has been reported to change the taste and smell and Yarrow (Achillea millefolium) is implicated in having the potential to boost Cannabis’ flavour. Lavender (Lavandula), Lemon balm (Melissa officinalis) and Pot marigold (Calendula officinalis) potentially augment terpene profiles as well as controlling pests while providing habitat for beneficial insects and providing good sources of nutrients. Whether terpene augmentation through companion plants is scientifically valid is unsure due to Cannabis research being stifled for decades. What has been proven scientifically, is that plants, bacteria, fungi and insects use terpenes to communicate with one another, themselves and other micro-organisms.
From Rosemary (Rosmarinus officinalis) for home-cooked-meals to colourful flowers serving to brighten up your garden, incorporating companion plants benefits the ecosystem surrounding your garden. Planting accompanying herbs and plants alongside Cannabis plants help recycle and to an extent buffer nutrient uptake, amplify flavours and serves as leverage in pest management. A well-fed plant is more likely to be disease-resistant. Permaculture techniques can build a plant’s resilience, making it stronger and healthier. Cannabis is a highly adaptable and durable plant, but diseases and pests pose ongoing risks in both indoor and outdoor cultivation. Monocultures are major targets for problematic insects and pathogens like powdery mildew. By diversifying their crop spectrum, growers are less likely to lose plants to disease and insect infestation. Companion planting also helps to create a stable, diverse habitat for a myriad of birds, bees and small animals, which interact in positive ways with their botanical counterparts.
Adapted from Companion Planting: Best Cannabis Neighbours with Marijuana not Monoculture, Companion Planting for Cannabis, CANNABIS NEWS JOURNAL: COMPANION PLANTING WITH CANNABIS, The Best Companion Plants For Your Cannabis Garden, Companion Planting for Cannabis: What You Need To Know and Enhancing Cannabis Terpene Profiles Through Companion Planting