5 Easy to Grow Mosquito-Repelling Plants
Before reaching for the chemical sprays, try planting these easy-to-grow plants which have natural mosquito-repelling properties:
Citronella is the most common natural ingredient used in formulating mosquito repellents. The distinctive citronella aroma is a strong smell which masks other attractants to mosquitoes, making it harder for them to find you. Although citronella is used in many forms, such as scented candles, torches and citronella ‘scented’ plants, the living plant is more effective because it has a stronger smell.
Citronella is a perennial ‘clumping’ grass which grows to a height of 5 – 6 feet. It can be grown directly in the ground in climate zones where frost does not occur. If grown in the garden or near the patio, it should be planted in the ‘background’, behind small decorative flowers and shrubs. In northern climate zones citronella can be grown in a large pot or planter, ideally with casters, so it can be rolled indoors during winter.
Also known as Beebalm, Horsemint is an adaptable perennial plant which repels mosquitoes much the same as citronella. It gives off a strong incense-like odor which confuses mosquitoes by masking the smell of its usual hosts.
Horsemint is a fast growing, shade-tolerant and drought-resistant plant which reaches a height and width of 2 – 3 feet. It does well in dry, sandy soil and can tolerate salty conditions, which is why it is often found in coastal and beach areas. Horsemint seeds can be sown indoors in trays for later transplanting, or sown directly into the ground in late summer in colder climate zones. Midwest and Eastern growing zones are favoured for growing horsemint.
Mature horsemint plants can be divided in spring and fall by dividing into small sections and transplanting into permanent locations. Horsemint can also be planted in pots for moving indoors in cold climate zones.
Horsemint leaves can be dried and used to make herbal tea. Its flowers will also attract bees and butterflies to your garden.
Commonly grown as ornamental border plants, marigolds are hardy annual plants which have a distinctive smell which mosquitoes, and some gardeners, find particularly offensive. Marigolds contain Pyrethrum, a compound used in many insect repellents.
Marigolds prefer full sunlight and reasonably fertile soil. Although marigolds can be planted from seed, starter plants are inexpensive and readily available at most garden centers. Although an annual, marigold will often reseed itself in favourable conditions, or the gardener can easily collect seeds for future germination. Established plants will need to be thinned, and flowers should be dead-headed to promote additional blooms.
Also known as Flossflowers, Ageratum emits a smell which mosquitos find particularly offensive. Ageratum secretes coumarin, which is widely used in commercial mosquito repellents.
Ageratum is a low-lying annual ornamental plant which reaches heights of 8 – 18”, and is easily recognized by its blue flowers, although there are varieties with pink, white and violet blooms. This plant will thrive in full or partial sun and does not require rich soil. It is often displayed in rock gardens where low-lying plants are favoured.
Although the leaves of Ageratum can be crushed to increase the emitted odor, it is not advisable to rub the crushed leaves directly on the skin.
Catnip is a natural mosquito repellent. In August 2010, entomologists at Iowa State University reported to the American Chemical Society that catnip is ten times more effective than DEET, the chemical found in most commercial insect repellents. According to Iowa State researcher Chris Peterson, the reason for its effectiveness is still unknown. “It might simply be acting as an irritant or they don’t like the smell. But nobody really knows why insect repellents work.”
Catnip, Nepeta cateria, is very easy to grow. This perennial herb is related to mint, and grows readily both as a weed and a commercially cultivated plant in most areas of the US.
While catnip will repel mosquitoes in close proximity to the plant, some people apply crushed catnip leaves or catnip oil for more robust protection. Bear in mind, however, that cats will respond to you similarly as they would respond to the plant itself. Cat owners may want to choose an alternative plant for repelling mosquitoes.