Spring has sprung, and the copious rains we received this past winter and early spring are showing themselves in the lush growth of grass, trees, shrubs and (dramatic pause) mosquitoes. I don’t know about your yard/garden/place, but I have to either slather myself with mosquito repellent or wear some netting before stepping outside, especially early in the day and early in the evening. I’ve heard neighbors complain that this year is far worse than previous years and I’m in agreement. I suppose the rain/sun/rain/sun/mist/sun/fog/sun combination is perfect for mosquito breeding grounds. So, what to do about these pesky little bloodsuckers?
One of the first things to do, which may not be possible depending on where you live and garden, is to empty out all standing water. That means tarps, saucers under pots, rain gutters, troughs with standing water, buckets, dog bowls, etc. Mosquitoes can breed in an incredibly small amount of water, such as a bottle cap. If you have necessary standing water, like a birdbath, you can use Bt, or Bacillus thuringiensis, which is deadly for mosquito larvae, but doesn’t harm wildlife, humans or birds. You can find Bt at your local nursery or hardware store. It comes in bits, dunks and other forms. I like to set up a Bucket of Doom™ in spots around my property. Put a few inches of water in the bottom of a 5-gallon bucket, then add some straw. Sprinkle a liberal amount of Bti bits, or part of a dunk, and the mosquitoes will lay their eggs in the bucket. The larvae will perish. Make sure to replenish the Bti every couple of weeks or so.
Another way to deter mosquitoes is to cultivate plants they don’t care for. Plant a half wine barrel or large pot with some of the following: bee balm, marigolds, spotted geraniums, lavender, sweet fern, citronella, rosemary, garlic, sage or catnip. (Though, if you plant the last one, I’m not responsible for all the neighbor’s cats coming into your yard.)
According to an environmental science teacher at the University of New England, placing these in strategic spots in your yard can help deter the little suckers. It’s important to “activate” the plants by brushing up against them. This releases the chemicals that make it difficult for mosquitoes to navigate and find prey (such as your tender flesh). They suggest planting something in the middle of the pot that you harvest regularly, like basil, or tomatoes, so that you brush up against the plants regularly. Given the success of tomatoes (or lack thereof) here on the coast, I’d go with basil or some other herb you use regularly.
Another colorful way to deal with mosquitoes is to attract birds and other insects that love to dine on larvae or adult mosquitoes. Swallows (all kinds) provide great pest control. In my area, the swallows returned last month. Set up a house that’s designed for swallows, or allow the cliff swallows to build one of their mud nests on your soffit or the eaves of the house. Preferably not right over the front door, as they do what birds do. I love watching the Violet Green Swallows swoop over my front yard, garden and orchard. Barn swallows can consume up to 850 insects per day. Other birds that dine on adult mosquitoes include Yellow Warblers, Downy Woodpeckers, House Wrens, Baltimore Orioles and hummingbirds. Encourage dragonflies to your yard, too, because in addition to eating adult mosquitoes, they also dine on the larvae.
Excellent ways to attract birds to your garden or yard include: planting native plants, never using broad-spectrum pesticides (they don’t just kill the “bad” bugs, they also kill all the beneficial ones, which have a much harder time bouncing back), providing shelter and cover for the birds, and keeping those cats indoors — or building a nice catio or cat run for them. (We have a cat run here at our place.)
Another excellent pest control critter is the bat. Some people freak out around bats but I promise they’re not going to fly into your hair. You can make a cozy spot for bats by putting up a bat house. According to Bat Conservation International, the bat houses should be mounted at least 10 feet above ground, and 12 to 20 feet is better.
Choose a sunny location on the east or south facing side of your house. Bat houses work best with at least six to eight hours of direct sunlight (if only partial day sun is available, morning sun is preferable). Bat houses should not be lit by bright lights, so installing near porch or security lights is generally a bad idea. Ideally, the houses will be within ¼ mile of a body of water.
You can even build your own bat house if you’re handy with a few power tools. Plans can be found at batcon.org.
If you choose to go the bat route, I encourage patience. We had three bat houses installed at the south end of our house more than a decade ago, and it took the bats a few years to decide that they’d set up house here. Now, I love going out in the early evening before dusk to watch the little insect munchers flit about over the garden and front yard. Little brown bats have been shown to devour more insects, including mosquitoes, than large brown bats. Fortunately, little brown bats are common in Humboldt County.
Now if you’ll excuse me, it’s time for me to go replenish my Buckets of Doom™. Happy hunting!
Julia Graham-Whitt (she/her) is owner and operator of the landscaping business Two Green Thumbs.
Editor’s note: This story has been updated to correct the name of the mosquito dunk chemical.
This article appears in Wide Open.