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| Citronella |
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.
When purchasing citronella, look for the true varieties, Cybopogon nardus or Citronella winterianus. Other plants may be sold as ‘citronella scented’, but these do not have the mosquito repelling qualities of true citronella.
When purchasing citronella, look for the true varieties, Cybopogon nardus or Citronella winterianus. Other plants may be sold as ‘citronella scented’, but these do not have the mosquito repelling qualities of true citronella.
My findings: if you live in northern climates, plant in planters with casters so it can be moved indoors during the winter months. It is a perennial in zones 10-12 and can be grown as an annual in other climates - plant after the ground has warmed.
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| Horsemint |
2. Horsemint
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 leaves can be dried and used to make herbal tea. Its flowers will also attract bees and butterflies to your garden.
Horsemint leaves can be dried and used to make herbal tea. Its flowers will also attract bees and butterflies to your garden.
My findings: Midwest and Eastern climates are favored for growing this plant - it especially prefers dry, sandy soil. Its often found around beaches, as it can easily tolerate salty conditions.
3. Marigolds
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.
Potted marigolds can be positioned near entrances to your home and any common mosquito entry points, such as open windows. The smell may deter mosquitoes from going past this barrier. While marigolds can be used as border plants around the patio, we do not advise putting marigolds on the patio table since the bright blooms may attract wasps.
Besides repelling mosquitoes, marigolds repel insects which prey on tomato plants, so you may want to plant a few marigolds in your tomato bed for added protection.
Potted marigolds can be positioned near entrances to your home and any common mosquito entry points, such as open windows. The smell may deter mosquitoes from going past this barrier. While marigolds can be used as border plants around the patio, we do not advise putting marigolds on the patio table since the bright blooms may attract wasps.
Besides repelling mosquitoes, marigolds repel insects which prey on tomato plants, so you may want to plant a few marigolds in your tomato bed for added protection.
My findings: This one might be a better option for me here in the Northwest. Marigolds prefer hardiness zones 1-11, and to be grown in moist, well-drained soil.
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| Ageratum |
4. Ageratum
Also known as Flossflowers, Ageratum emits a smell which mosquitos find particularly offensive. Ageratum secretes coumarin, which is widely used in commercial mosquito repellents.
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.
My findings: This annual thrives in full OR partial sun and blooms all summer and into fall.
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| Catnip |
5. Catnip
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.”
In the laboratory, Peterson put groups of 20 mosquitoes in a two-foot glass tube, half of which was treated with nepetalactone, a biologically active characteristic constituent of catnip. After 10 minutes, only an average of 20 percent – about four mosquitoes – remained on the side of the tube treated with a high dose (1.0%) of the oil. In the low dose test (0.1%) an average of 25% – five mosquitoes – stayed on the treated side. When the same tests were conducted using DEET (diethyl-meta-toluamide), approximately 40 to 45% – eight to nine mosquitoes – remained on the treated side. A ten-fold higher concentration of DEET was required to obtain results similar to those of the Catnip.
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.
My findings: Grows in hardiness zones 3-4... and note to self: this plant attracts cats so do not plant in the garden! Plant in other areas of your yard that you do not mind cats hanging around near.
Hopefully some of this information is useful to you and one or two of these can be intermingled into your gardens. Happy mosquito-free summer!
