Using Companion Planting to Deter Pests in Vegetable Gardens
Many vegetable gardeners use a technique called companion planting to reduce pest problems. A companion plant is one that provides some sort of benefit to other plants growing nearby. Some plants are grown together because they seem to increase each other's yields. However, the companion plants discussed here repel pests.
Is that really possible? Some people swear by it. It is true, that a variety of plants, herbs, and flowers provides a diverse ecosystem so that predatory insects are more likely to hang around and take care of the bad guys. Besides, trying some of these combinations certainly won't hurt your garden.
These plants are thought to repel specific pests; plant them near crops where these pests are a common problem:
Anise planted among members of the cabbage family (cabbage, broccoli, cauliflower, kale, and so on) is said to repel imported cabbage worms.
Basil is said to repel whiteflies, aphids, and spider mites; it's a good companion to tomatoes because these are insects that feed on tomato plants.
Catnip is said to repel some types of aphids, flea beetles, squash bugs, and cucumber beetles.
Garlic may repel nematodes and other soil insects.
Leeks are thought to repel carrot flies.
Marigolds planted around vegetables are said to repel root nematodes, Mexican bean beetles, and Colorado potato beetles.
Mustard greens are supposed to repel aphids.
Nasturtiums are said to repel Colorado potato beetles.
Radishes may repel striped cucumber beetles.
Ryegrass may repel root-knot nematodes.
Southernwood may repel moths and flea beetles.
Tansy is supposed to repel some aphids, squash bugs, and Colorado potato beetles as well as ants.
White clover may repel cabbage root flies.
Wormwood may repel flea beetles.
Many herbs, such as rosemary, oregano, and coriander, also are said to repel pests. Smaller companion plants, such as marigolds, can be interplanted with vegetables. Taller or more vigorous plants, such as ryegrass or wormwood, should be planted nearby — but not among — vegetables. You don't want them to overwhelm your veggie plants.