Farmers have long been experimenting with wild plants to use as repellents, intercropping them between vegetables or planting aromatics along the edges of crops.
The idea is to create associations of beneficial plants that protect crops from pests, keep them away or promote the development of their predators.
The list is a compilation of popular wisdom, I don’t know if there are any scientific studies on this. In any case, even if some do not keep what they promise, we always increase biodiversity, at least this would favor insects which can act as predators against many pests.
In addition, the interspersing of strong-smelling plants (aromatic, garlic, etc.) can confuse the pathogens of carrots or other plants with a more delicate smell. Planting showy flowers or plants with abundant foliage can reject pathogens in search of their hosts that are less visible and normally contrasted with brown soil…and vice versa. Almost all plants used as repellents (or attractants to predators) use the mechanism of increasing attraction on some or decreasing or masking on others.
- Mugwort: Repels weevils, mites and caterpillars in corn plantations.
- Garlic: Repels nematodes. Natural bactericide and fungicide. It is used in carrot and strawberry crops.
- Basil: Repellent whiteflies, mosquitoes, flies, bed bugs. It is used in the cultivation of tomatoes and peppers. Attracts pollinators by increasing agricultural production. Repels flies and mosquitoes, planted near doors or windows, either on the ground or in pots, prevents these insects from entering the house. In the garden, it can be planted next to the tomato to repel insects that attack it.
- Borage: Borage is very useful in the garden because it attracts insects that feed on crop pests.
- Calendula: In potato, cabbage and horticultural crops in general, it repels aphids, bedbugs, whiteflies and worms (nematodes). Scares away the asparagus beetle. It also attracts a number of beneficial insects to the garden.
- nasturtiums: With broccoli, it protects them from aphids. With pumpkins, it repels worms. It is also used to repel cottony aphids, common aphids, squash bugs, striped beetles, snails and ants. It also attracts many beneficial insects such as bees or bumblebees.
- Onion: Protects most plants from a large number of pests and diseases. Onion plants prevent gray rot of strawberries. It is said that a string of onions around the vegetable patch will keep rabbits away.
- chive: Attracts bees. It can be planted under apple trees to prevent apple rust. It is also used to repel the carrot fly.
- dill: Dill, as well as fennel, attracts hoverflies, beneficial insects for the orchard and the garden, which feed on the larvae of harmful insects. This helps control parasites naturally.
- Sunflower: Attracts bees and other pollinators.
- Pepper mint: Repels cabbage aphids. It drives out cabbage moth and aphids. Attracts bees and beneficial insects. Helps control pests and insects.
- Florence Fennel: Fennel and dill attract beneficial insects to the orchard and garden, they feed on the larvae of harmful insects. This helps control parasites naturally. It is a very invasive plant, so interplanting crops is not recommended.
- Hyssop: they hunt caterpillars, aphids and snails. Repels cabbage moth. The flowers attract bees and butterflies among others.
- Lavender: attracts bees, bumblebees and butterflies. It keeps aphids away from roses. Prepared against ants on plants (repellent): 300 grs. of lavender leaf per liter of boiling water. Leave to cool and spray on the plants.
- Chamomile: attracts hoverflies and bees.
- Balm: attracts pollinators while repelling mosquitoes, whiteflies and other insects. It should be reserved for the outer edge of the orchard, as it is very invasive.
- Marjoram: Attracts beneficial butterflies and bees, also very useful for pest control in orchard and garden.
- mint: Mint repels aphids and other harmful insects. Mint on the edges of the garden stops the entry of ants (avoiding the aphids they displace), fleas and cabbage white moth. It also repels rodents. Attracts bees, bumblebees and butterflies. Helps control insect pests.
- Nettle: Plant that attracts beneficial insects. Stinging nettle aphids do not attack other plants and are among the first in the spring when other food is scarce, feeding on beneficial insects such as ladybugs newly awakened from hibernation. Additionally, some butterflies such as pearly, peacock, and red admiral lay their eggs on nettle leaves. Nettle is a conservative plant that prolongs the life of neighboring plants and protects them from diseases caused by fungi.
- Pyrethrum: It is a “daisy” whose flowers produce pyrethrum, a widely used natural insecticide. It is very invasive, so it is grown in borders or in separate pots.
- Rosemary: attract pollinators. Better in pot and with little irrigation because in abundance of water it produces little essence at the same time as it is very invasive. Hunt bed bugs in carrot, cabbage.
- Street: A good insect repellent can be made by crushing 200 grams of rue, adding a few sage leaves to 1 liter of water, letting it sit for 48 hours and spraying. This flowering plant attracts hoverflies. Repels slugs, moles, flies, mosquitoes, threadworms and Japanese beetles.
- Sage: Repels whiteflies, cabbage moths and slugs. It is very invasive and its roots produce substances that inhibit the growth of other plants, so it must be kept in pots or far enough away from the crop.
- Marigolds: Its roots excrete a substance that repels garden nematodes.
- Thyme: It is a cabbage moth repellent. Better in pot and with little irrigation because in abundance of water it produces little essence at the same time as it is very invasive. Thyme, like other aromatics, attracts beneficial bees and repels harmful insects. For example, in the garden, it repels flies that attack cabbage.
And you, do you use repellent plants?