Ticks are dangerous garden pests that cause Lyme disease and other problems. Ticks are problematic because they are attracted to both humans and animals, and may infest your household pets. Plants that keep ticks away keep the garden safer for everyone, and many offer other pest-prevention applications in addition to repelling the blood-sucking insects.
Many fragrant herbs are repellent to ticks. Lavender, Lavandula, emits an aroma that many humans enjoy, but ticks will avoid the flowery scent. Rosemary, Rosmarinus officinalis, is another tick-repellent that's so powerful, sprigs of the plant may be sprinkled around the garden to keep the pests away. Rosemary also repels aphids, mites and flies. The smell of sage, Salvia, a common kitchen spice and garden herb, is also distasteful to ticks.
Plants in the mint family are also aromatic, and some of them may keep ticks away. Ticks are repelled by the strong smell of catnip, Nepeta cataria, which also repels beetles, aphids, ants and cockroaches. Pennyroyal, Mentha pulegium, the most strongly-scented mint-family plant, produces purplish flowers that give off a perfumed scent. Pennyroyal is so effective at repelling ticks, it may be powdered and sprinkled all around the garden to keep them away.
Mexican marigolds, Tagetes erecta, are one of many tick-repellent flowers. The strong odor emitted by Mexican marigolds keeps the insects away. Marigolds, Calendula, repel beetles, tomato worms and ticks. Borage (Borago), chrysanthemums, cosmos, rue (Ruta) and sunflowers (Helianthus) are general pest-repellent flowers that keep many different types of insects away.
Rose geraniums, Pelargonium graveolens, have a very strong scent that's apparent when the leaves and petals are brushed or crushed. When such abrasions occur, the plant releases a strong-scented oil that keep ticks, mosquitoes and fleas away.