While summer’s warm days and long nights afford us ample time to enjoy the great outdoors, summer is also prime time for mosquitoes, bloodsuckers that can both ruin our outdoor enjoyment and carry diseases such as West Nile virus. Perusing the bug-repellent aisle at your grocery store or pharmacy, you’ll find a swarm of mosquito-control products based on the chemical DEET. But before you spray yourself, your family and your yard with these products, consider the health effects. A study by the National Park Service found that test groups exposed to DEET reported side effects including nausea, headaches, dizziness, skin irritation, rashes and numb or burning lips. Researchers at Duke University also found that long-term exposure to DEET can kill brain cells and cause behavioral changes in rats. Fortunately, we don’t have to rely on chemicals to keep pesky and potentially dangerous mosquitoes at bay. Try some of our favorite natural mosquito control methods instead.
Repel Mosquitoes Naturally
Some garden plants naturally repel mosquitoes. Rose-scented geraniums contain the natural insect repellents citronellal and geraniol–some gardeners report swishing their hands through the leaves is enough to deter mosquitoes. Lemon balm (Melissa officinalis), which is easy to grow from seed, contains the repellents citronellal, geraniol and geranial. And the essential oil in catnip (Nepeta cataria), nepetalactone, was found to be about 10 times more effective at repelling mosquitoes than DEET, researchers at Iowa State University found.
Gardeners also report anecdotally that crushing handfuls of basil (Ocimum basilicum), lemon thyme (Thymus x citriodorus) and lemongrass (Cymbopogon citratus) can repel mosquitoes for short periods–usually less than 30 minutes. To try these plants, just crush a handful of leaves in your hand and rub them on exposed skin. (Use any herb with caution until you know how your skin will react.)
Another natural solution may be soybean oil. In a study by the New England Journal of Medicine, a soybean oil-based repellent offered protection from mosquito bites for 1.5 hours.
Plants that Repel Mosquitoes
A number of smart yard management techniques can help reduce the number of mosquitoes in an area. First, eliminate breeding places: any objects that can hold as little as a few tablespoons of water for seven to 10 days–the time it takes for eggs to hatch and larvae to mature. Commonly overlooked breeding spots include old tires, clogged gutters and abandoned tubs or buckets. Change the water weekly in bird baths, wading pools, outdoor pet bowls or anywhere else you might find standing water around your property.
If your yard contains large water troughs, ponds or other areas with standing water, you can use Bt (Bacillus thuringiensis israelensis), a naturally occurring bacterium that kills mosquito larvae, yet is nontoxic to people and fish. Many garden centers sell mosquito dunks or granulated products containing this fast-acting biological larvicide.
When it comes to treating your lawn, avoid spraying the area with broad-spectrum insecticides. Many of these sprays contain insecticidal compounds known as pyrethrins. Extremely toxic to bees, fish such as bluegill and lake trout, and slightly to moderately toxic to bird species, these chemicals also have been associated with (in rare cases, dangerous) allergic reactions in humans, and anemia and disruption of sex hormones in lab animals. Along with pest insects, insecticides can also kill natural mosquito predators–most of which take longer to repopulate than the mosquitoes themselves. Keeping backyard chickens also can be an effective way to reduce mosquitoes and other insect pests. Learn about how to select a breed, build your own coop and more in “What the Cluck! Raise Backyard Chickens.”
A few other outdoor habits can help repel mosquitoes naturally. Fans may be a good way to help shoo the pests off your deck or patio–researchers believe fans work because they help dispel the carbon dioxide we exhale, which is how mosquitoes locate us. If you have an unscreened porch, install an overhead ceiling fan: You’ll be cooler and may get fewer bites. Burning citronella candles is effective and one of the easier natural mosquito control methods. In one study, the candles were shown to reduce mosquito bites for those near them while they were being burned–but their effectiveness is only in the immediate area if wind is low, so it’s best to pair their use with a topical repellent. You will also find commercially available mosquito traps, but The American Mosquito Control Association has determined that the traps, designed to lure and kill large numbers of pests, are only effective against certain species. Placing baited traps on your property could, in fact, attract mosquitoes that may not come otherwise, and at $200 to $500, you will want to get a local endorsement of effectiveness before investing in such products.
You can reduce your personal attractiveness to mosquitoes by avoiding highly perfumed soaps and shampoos and wearing loose-fitting clothing, which helps form an air barrier between you and the bugs. Mosquitoes are most attracted to areas of the body where the skin is thin and blood vessels are close to the surface such as ears, wrists and ankles, so pay extra attention to covering or applying natural repellent to these areas. Opt for light- or neutral-colored clothing, which is less attractive to mosquitoes than dark or bright floral colors.
Be diligent about using your herbal mosquito repellent. Most herbal repellents work for a shorter time period than their chemical counterparts. The key to using any plant-based repellent is to watch how it’s working. Immediately after application, mosquitoes will not light on your skin; as the effectiveness wanes, they will light but not bite. That’s your signal to apply more repellent because the third stage is near–when the mosquitoes light and bite.
Herbal Mosquito Repellent Recipe
To avoid using DEET-based products, make your own herbal mosquito repellent. The following essential oils will naturally repel mosquitoes–for a stronger formula, try mixing several oils together. Experiment to see which oils work best with your body chemistry. Always test essential oils on a small patch of skin before applying liberally, and use extra caution with children. Most essential oils are not recommended for use on children younger than 2.
- Lemon Balm
- 2-1/2 teaspoons total of any combination of mosquito-repelling essential oils
- 1 cup 190-proof grain alcohol (available in liquor stores)
1. Place ingredients in a jar with a tight-fitting lid and shake vigorously. Transfer to small bottles for storage. To use, rub a small amount on exposed skin or dab on clothing.
What Doesn’t Work
Several studies have found that installing a bat house, sometimes cited as a mosquito deterrent, is ineffective at controlling mosquitoes because bats prefer to dine on larger insects. Ultrasonic devices and outdoor bug “zappers” also don’t help control mosquito populations.