Various herbs have been used for centuries to help keep mosquitoes from landing on skin and biting. However, over the last century with the emergence of new products containing synthetic chemicals such as DEET, many common herbs with insect repelling qualities are no longer being used. However, plants can be used to repel many biting insects.
To keep away mosquitoes during picnics outdoors burn Citronella candles. Lemon grass, Cymbopogan nardus, a course grass-like plant, contain Citronella oils. As well as its essential oil repelling insects it also may help to deter unwanted cats in the garden. Burning candles with wicks saturated with the herb, myrrh is also quite effective at keeping many insects away. Egyptians used myrrh as a fumigant.
Indoors try placing the scented geranium, Pelargonium citrosum Vanieenii at strategic locations such as near doors and windows. "Vanieenii" has a good reputation for warding off bugs. Many other scented geraniums besides "Vanieenii" also contain Citronella oils which help repel insects.
If insects such as mosquitoes have already become a problem many herbs can be used directly on the skin as repellents. Infusions of 50% Chomomile and 50% Elder leaves dubbed on skin are effective for up to 20 minutes. Infusions are much like making tea, boiling water is poured over the herb and the herb/water mixture is then left to steep for 10 to 15 minutes. The remaining liquid is strained and used as the repellant.
As well as infusion, other properties of herbs such as their essential oils can be used as repellents. Essential oils such as Lavender, Tea tree oil and Citronella from the stone root, Collinsonia canadensis an be worn on the skin and in hair to effectively keep mosquitoes away. It is best to dilute these powerful essential oils in a little olive oil and test this new mixture on a patch of skin before applying to ones entire body. Pennyroyal has also been used throughout history to repel insects. However, the oil of Pennyroyal is extremely toxic and should only be used by certified herbalist.
In the event mosquitoes were not repelled effectively, many herbs can be used to relieve the itching from bites. Wash insect bites with a Tea tree oil based soap and rinse with witch hazel. Next, dab freshly washed bites and lemon juice or cider vinegar. Before bedtime, apply lavender oil or cinnamon oil by rubbing on the affected area. As well as helping repel mosquitoes these oils also take away itching from bites.
Photograph courtesy of Digital Frog International.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010