A whitefly infestation weakens vegetable plants and flowers. Control whiteflies with companion planting. Whiteflies find basil, nasturtiums and marigolds unpleasant. Instead of using chemical pesticides, add these plants to the flower garden. Not only will they keep whiteflies at bay, but also they attract beneficial insects.
Whiteflies drain plants of sap by sucking the liquid from leaves. The insects collect on the underside of leaves and feed on the plants. Leafy vegetables and ornamental flowers are particularly likely to suffer from whitefly infestations. Look for whiteflies during the day on the underside of leaves. The tiny insects grow about 1/16 inch long with moth-like wings and bodies, according to the University of Minnesota Extension. Infestations weaken plants, causing the leaves to turn yellow.
Planting nasturtiums among vegetable plants and ornamental flowers keeps whiteflies away, according to the Cornell University Cooperative Extension. Sow nasturtium seeds in the spring around cabbage starts, cucumber plants, cabbage and tomato seedlings and around radishes. Not only do nasturtiums deter white flies, the flowers are edible adding color to salads and other spring and summer foods. The plants thrive in full sun.
Marigolds make a suitable all-around companion plant in the garden. The strong-smelling flowers deter whiteflies and other garden pests, including slug, according to Brigham Young University. Plant marigolds in the spring throughout the garden. Space the plants 6 to 24 inches apart along border areas and among vegetables and flowers. The bright, colorful flowers bloom through summer and fall, attracting butterflies and other pollinators.
Basil’s pungent fragrance and rich flavor comes from essential oils in the leaves. Basil, used as a companion plant, discourages whitefly infestations. Plant three to six basil plants around the base of tomatoes. Tomatoes and basil pair well in the kitchen, and basil improves the flavor of tomatoes when grown together, according to the Cornell University Extension. Basil also discourages aphids, tomato hornworm and mosquitoes, according to Brigham Young University.