While most flowers are pollinated by insects, some varieties not only fail to attract bugs but go so far as to repel them. While even these flowers usually attract a few helpful insects, they keep off so many harmful species that they can be planted in your garden as a protective measure for your vegetables.
Although harmless to humans and mammals, chrysanthemums are deadly to many species of insects. The crushed, dried petals have been used as a natural insecticide for centuries, but the live plant also repels some types of bugs. White chrysanthemums in particular are notable for keeping away Japanese beetles, those pesky ladybug lookalikes that often swarm near the end of summer.
The geranium is a flower that attracts some harmful bugs but repels others, a feature that can be put to good use in a garden. Because Japanese beetles and cabbage worms will do anything they can to avoid the flowers, geraniums form a veritable barrier of defense for peppers, tomatoes, cabbage, roses, corn and even grapes when planted nearby. Beet leafhoppers, on the other hand, are extremely attracted to geraniums, allowing them to serve as a distraction from more important plants.
Lavender is known to repel both moths and fleas, and is even capable of doing so when cut and dried. When planted near produce, the flowers can protect it from other harmful bugs, as well. Whiteflies will not touch vegetables when lavender is growing nearby, and the codling moth, a scourge of fruit trees, will avoid any such trees that have lavender planted around the base.
Crushed pennyroyal leaves, rubbed on your skin, will repel a wide variety of pests, including flies, mosquitoes, gnats, chiggers and ticks. The live flower additionally frightens off fleas, making it a remarkably useful bug-repelling plant. Caution must be exercised, however, because insects are not the only creatures for whom pennyroyal is harmful. Pennyroyal is poisonous to cats, for example.
The petunia is another powerful bug repellent — petunia tea can even be used as a spray to keep away insects. Among the many species that find the petunia distasteful are Mexican bean beetles, asparagus beetles, tomato worms, cabbage maggots, leafhoppers, aphids, fleas and ticks. Any vegetable planted near petunias is sure to be protected from a wide variety of pests.