Insects have one of the most important ecological roles in nature, but bites from mosquitoes, gnats, flies, and no-see-ums are highly annoying. To prevent their itchy and painful punctures, many people slather themselves in chemical insect spray (DEET, one of the worst offenders, is neurotoxic and has been detected in groundwater). They don’t realize that they can repel bugs—at least partially—using the power of plants.
Even those without a full garden can employ plants in containers on balconies or patios.
In this article, you will learn about 12 plants that could help you manage the insect population in your garden. As a bonus, you can use most of them to make your own natural bug repellent. Even just crushing the leaves in your hands and rubbing the oils onto your skin while you’re working in the garden can deter some insects from hovering and biting. This may not be as effective as conventional repellent formulas, but it will help somewhat.
How Do Plants Repel Insects?
The smell of some herbs and flowers, resulting from the distribution of tiny globules that contain essential oils, can help to ward off insects. High temperatures can cause the globules to become volatile, evaporating the essential oils and turning them into vapors. The many globules on the underside of rosemary leaves are one of the best examples of this.
One study on the efficacy of plant repellents explains, “This repellency of plant material has been exploited for thousands of years by man, most simply by hanging bruised plants in houses, a practice that is still in wide use throughout the developing countries.” Plants have also long been used in “crude fumigants” or applied in oil formulations to skin and clothing.
Please realize that this probably isn’t enough to make your garden totally insect-free. Dr. Bodie Pennisi, a professor and landscape specialist at the University of Georgia’s Griffin campus, says it’s unclear how many plants would be needed to effectively repel insects and how close together they would need to be planted. But who would want a bug-free garden, anyway, when bugs are food for so many birds and other beneficial critters? The goal should be reduction, not elimination.
One of the best things people can do to hold down mosquito populations in particular, she advises, is to eliminate any standing water, which is where mosquitoes breed.
Tip: Before you get rid of your birdbath, consider instead adding an aerator or agitator, which allows you to leave important water out for organisms that need it but will disrupt the stillness that mosquitoes need to breed.