Sunday, July 31, 2016

Do Plants Repel Mosquitos? by Donna Duffy

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 Ask any gardener – they will tell you that it’s a buggy year. The mosquitos seem especially ferocious this summer, which made me wonder if there are any plants that will repel mosquitos. Here’s what I learned from CSU’s research.

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Rumors and misinformation abound regarding plants that will repel mosquitoes in home landscapes. Common plants purported to repel mosquitoes include catnip, peppermint, rosemary, marigolds, Eucalyptus and Artemisia species, to name a few. None of them will repel mosquitoes by merely growing in a landscape. The volatile oils purported to have repellent properties are released when plants are crushed or burned. No data exists to support their effectiveness as repellents. Check out Plantalk’s publication Do Plants Repel Mosquitos for more information. 

Since we can’t depend on landscape plantings to repel mosquitos, the next best thing is to try to repel them by other means. To keep mosquitoes away during outdoor gatherings, burn Citronella candles. Lemon grass, Cymbopogan nardus, a course grass-like plant, contains Citronella oils. Burning candles with wicks saturated with the herb, myrrh is also quite effective at keeping many insects away. In fact, ancient Egyptians used myrrh as a fumigant.

If insects such as mosquitoes have already become a problem, many herbs can be used directly on the skin as repellents. Infusions of 50% Chamomile 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 can 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. More information can be found in CSU’s publication Plants Help Keep Mosquitos Away.

Don’t let the mosquitos chase you indoors – grab a repellant and make your stand!