What Do Nasturtiums Repel?

Insects Repelled

• The fragrant, colorful nasturtium may effectively repel the cabbage looper, cucumber beetle, imported cabbageworm, squash bugs and whiteflies. Nasturtiums may actually attract aphids, making this plant an excellent trap crop for that type of pest. Once a nasturtium is covered with aphids, the plant can either be removed and destroyed or treated to kill the aphids. These fast-growing plants can typically outgrow aphid damage quickly. This plant can also draw slugs and snails away from other desirable vegetation.

Nasturtiums as Companion Plants

• The ability of the nasturtium to repel or attract certain pests makes it most valuable around plants that are bothered by these types of pests. Nasturtiums are good companions to squashes (Cucurbita spp.), tomatoes (Lycopersicon esculentum), cucumbers (Cucumis sativus), beans (Phaseolus vulgaris) and members of the cabbage (Brassica oleracea) family. Nasturtiums are also good for planting around fruit trees, where they will draw aphids from the tree. The bright flowers of nasturtiums also help to draw pollinators to the garden. These plants may also improve the growth and flavor of cucumbers they grow near.

Nasturtium Cultivation

• Nasturtiums require a site in full sunlight to perform well. They prefer well-drained, moist and sandy or loamy soil. Soaking seeds in water for 24 hours or using a file or sandpaper to scratch the seed coat prior to sowing the seeds will encourage germination. This plant will flower best in soil that is nutritionally poor, producing few flowers and lush vegetative growth in rich soil or where it is fertilized.

Other Insect Repelling Plants

• In addition to nasturtiums, several other plants are also excellent for companion planting. Mints (Mentha spp.) and catnip (Nepeta cataria) repel many of the same pests as nasturtiums. Other valuable companion plants include most aromatic herbs, Allium species like onions and garlic, dill (Anethum graveolens) and marigold (Tagetes spp.).