Companion planting is placing other species near or among cannabis plants for a benefit. Common goals are attracting predators and pollinators (flowering plants such as yarrow, alyssum, dill), trapping pests away from the crop (trap crops), covering bare soil (clover and other cover crops) and fixing nitrogen (legumes) in living-soil beds.
In practice
Outdoors and in living-soil beds, low-growing cover crops reduce evaporation and keep soil life active. Flowering herbs can support populations of beneficial insects such as hoverflies, lacewings and predatory wasps, which is a recognised integrated pest management tactic in other crops. Specific claims, such as basil repelling spider mites, are mostly anecdotal for cannabis.
Companions can compete for light, water and nutrients if crowded, and some, such as clover, can host pests too. Keep them low and away from stems.
Don't confuse with
- Cover crop: one kind of companion, grown mainly to protect and feed soil.
- Beneficial insects: the predators companions help attract; covered under pests.
