Garlic gives off a scent that repels insects.
Plants have defense systems in place to ward off predators, and part of this defense system in many plants includes their smell. What smells nice, floral and clean to us may actually annoy and repel hungry bugs. Using this knowledge, you can help keep your gardens and home safe from insects while minimizing the use of chemicals. Does this Spark an idea?
Gardens
Take advantage of bug-repelling scents by distributing bug-repelling plants around your garden. This is called companion planting. Cornell University notes vegetables and herbs like garlic, chives, tansy, basil and onions are very effective at repelling insects, and the university suggests mixing in plantings such as these around other plants. Michigan State University Extension suggests using mint as a sort of barrier plant. Many insects, including flies and ants, detest the scent of mint and peppermint, and the extension recommends planting mint around your home to ward off flies.
In the Home
Mint and basil are pest control champions in the home, as are cloves and oranges. Michigan State University Extension notes flies avoid clusters of cloves, and the scent from a freshly scratched orange peel can act as a general deterrent. Basil gives off a strong scent that fleas do not like, and the extension notes that one pot of basil on a table can help keep them away.
Caution
Not all plants used for pest control are nontoxic, warns Michigan State University Extension. The scent isn't necessarily the problem, but the plants can contain fragrance-emitting essential oils that cause harm to humans and animals. Plants like pennyroyal have a reputation for repelling fleas, but the oil and teas made from the leaves can be deadly. The extension recommends scattering the shavings and leaves of pennyroyal and sassafras, for example, near a pet bed to ward off fleas, but you must take care not to let children or animals put the shavings or leaves in their mouths.
Myths
Many plants have a good reputation for repelling insects, but some of those reputations are undeserved. For example, Washington State University Extension notes that the "mosquito plant," Pelargonium citrosum "Van Leeni" doesn't really repel mosquitoes. It does smell like lemon, but insects won't care. Another very common semi-myth is marigolds, which are supposed to repel insects, thus saving any nearby plants. While marigolds can repel soil nematodes, Washington State University Extension notes that's the flowers won't ward off other insects.
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