These plants are ideal for gardeners, to maintain a healthy balance in cultures. Planting these species in cultivated plots helps attract auxiliary insects to limit the proliferation of parasite insects. The latter are sometimes simply repelled by the smell of the plants (lavender, sage, rosemary, rue, cotton lavender). Other plants are used macerated, infused, or decocted and transformed into insecticide, insectifuge, fungicide or fertiliser (stinging nettle, tansy, comfrey, horsetail, fern, etc.).