Portland is beginning to see signs of spring as green shoots push their way through the soil, flowers bloom, and its native winged critters return to the city. Bats, like many birds, are migratory creatures that return to Portland in spring, around the same time our insect population rises. While easily associated with country living, many urban dwellers are unaware of the bat population in their area. However, some Portland gardeners understand the benefits bats have to offer and welcome bats into their garden.

Benefits of Bats: The DEET Alternative

Bats can eat up to 500 mosquitos in an hour.
Bats can eat up to 500 mosquitos in an hour.

DEET is the chemical agent found in mosquito repellent that is applied to the skin. While it may keep the mosquitoes away, it can also be absorbed by the body during application and use. DEET can cause skin reactions and directions must be followed closely to avoid any more serious side effects (e.g. don’t use on young children or anywhere that the skin is broken).

Instead of using DEET, why not consider the mammal alternative?

Bats offer serious pest control for the outdoor enthusiast. The little brown bat, Portland’s most common bat, can eat about 500 mosquitoes in an hour. A bat can do more to diminish the mosquito population at your home than a yard full of citronella candles.

Beyond just mosquitoes, bats will help reduce the population of bugs that have an eye for your veggies. These little eating machines can do a lot to ensure your crops stay safe into the night.

Another Bonus—Guano!

Bat guano makes an excellent fertilizer.
Bat guano makes an excellent fertilizer.

Bat guano can enrich your soil and provide vital nutrients to your garden. Buffalo Gardens owner Sandra Galli notes that guano has different gardening uses depending on its age and chemical balance. “Regular guano is higher in nitrogen, which is what most people want, and lower in phosphorous. Aged guano is just the opposite, lower in nitrogen and higher in phosphorous,” she says. The higher nitrogen content is best for leafy greens. Phosphorous is essential for blooms and fruiting plants, like tomatoes and fruit trees. If you visit Buffalo Gardens, Galli can guide you in selecting fertilizers that will suit your garden’s needs.

Lea Bergman, a Northeast Portland resident, has been collecting and utilizing her bat’s guano for about 15 years. “I just put it right in my garden, because it’s not hot like chicken manure,” says Bergman. Over the years, Bergman has developed quite the bat sanctuary at her British Columbia home and has begun transporting the guano across the border. She reports seeing bats visiting her yard every summer.

Here’s how you can go about bringing bats to your own garden:

Attracting Bats to Your Garden: To the Bat House!

some of the bat houses available at The Backyard Bird Shop.
Some of the bat houses available at The Backyard Bird Shop.

The best way to bring these beneficial creatures into your garden is to put a bat house on your property. If you’re a little frightened by that idea, maybe this will help: It’s estimated that less than 1% of the bats in the U.S. have rabies. “Bats get a bad rap about rabies, but we’ve long discovered you are less likely to get rabies from bats than [from] a raccoon,” says Darleen Betat, biologist and employee at Backyard Bird Shop. Oregon bats prefer insects, not people. They are docile animals that have no interest in being around you, unless you happen to attract lots of bugs.

If you are looking for a quick and easy way to bring bats to your home, you can pick up a ready-to-mount bat house, like the ones sold at Backyard Bird shop.

Bat House Tips

  • Paint the house in a dark-colored, water-based stain or paint to help hold in heat.
  • Choose a spot that gets about six to eight hours of sunlight (facing south to southeast is best)
  • Mount the house 12-15 feet high in a place that will be sheltered from the wind.
  • The entrance should be free of branches or any other objects that may block the entrance.
  • It is ideal, but not necessary, to place the house near a body of water.

When people ask Betat about the prospect of bats in their area, her first question is, “Have you seen bats?” This isn’t an all or nothing question, but according to Betat, you are more likely to get bats in your bat house if you’ve already seen them in your area. Otherwise, it may take a season or two until the house is occupied. “There is no guarantee in nature,” says Betat. “It’s hard to predict, but they are wonderful creatures and if you’ve got one, they will do a phenomenal job for you.”