I've heard from several people recently all of whom have pretty much the same problem: they're being bothered by wasps while they're outside tending to their plants and other landscaping. Typical of the complaints was this one from a reader who signed the e-mail R. Higdon: "I'm being barred from my gardening by a recent invasion of wasps! They're everywhere: under the eaves of the house, under the rails of the deck, in the oak trees -- I even found one starting a nest in the bird feeder. What can I do to convince them to leave and to never come back?"
I don't know anybody who actually enjoys the company of wasps while working or relaxing outdoors. Should we be bracing ourselves for a nationwide plague of wasps? Is the terrifying scenario from the movie, "The Killer Bees" about to become a reality?
The answers to those questions are "No" and "No".
As Spring spreads across America, we are seeing more activity from wasps as they emerge from their nests. We begin to notice them more right now as they've been out of sight (and thus out of mind) since last Fall.
Most of the wasps we see in North America are those known as Paper Wasps and Bald Faced Hornets, although many people tend to lump them all together as "Yellow Jackets" and sometimes confuse them with their chubby little cousin, the Honey Bee.
Bald Faced Hornets are both quite aggressive and fast, a nasty combination. They build globe-shaped nests up to 12 or more inches across, usually in trees or large shrubs, and sometimes in sheltered sites on the sides of buildings or even in the ground.
Paper Wasps are less aggressive but their nests can be harder to find. They are quite likely to make their home in YOUR home: underneath soffits, under the decking, or in the wall cavities behind the siding.
If you decide to try and destroy a colony of wasps, you must wait until late evening when the insects are all tucked up inside and are less likely to sting you. And unless you're auditioning for a Warner Brothers cartoon, don't whack the nest with a baseball bat. So how DO you do it?
If the wasp nest is in the ground, pouring soapy water into the entrance should do the trick, according to advice from the University of Minnesota Extension Service.
For wasp nests that are exposed above ground, such as those hanging from a tree, your best bet is to spray the entire exterior with a solution of a concentrated insecticide such as Cypermethrin. Once the outside is saturated, spray directly into the entrance hole.
As for Paper Wasps, the best time to remove their nests is during the winter while there are no live wasps in them, according to experts at the College of Agriculture and Home Economics at New Mexico State University. However, I believe it is now too late (and too risky) to try that this year. For Paper Wasp nests that are in "hidden" locations such as underneath fascia boards or behind siding, use a dry dust treatment rather than a liquid. First, determine when the wasps are entering and exiting. Then, in the late evening, use an applicator to blow the dust into the main entrance. Dry products, such as Drione, are almost as fine as smoke and will find their way into all the cracks and crevices where the wasps are snoozing.
It might be tempting to block up that entrance in your siding on the assumption that the wasps will be sealed in the nest and die. Resist the temptation! Many wasps will escape into your home through cracks in the walls or floors and through light fixtures and wall plates. You really don't want to share your home with a colony of homeless wasps!
It's hard to convince wasps to leave and never come back, but there are commercial sprays available that you can dilute with water and spray around the outside of your house and on trees and bushes. Repeat the spraying about once a month during the spring and summer and you'll discourage the wasps from moving in.
Of course, you might decide that the better part of valor is to call in the exterminator, so you can devote your energies to taking care of your gardening and landscaping without worrying about that familiar buzzing noise.
A member writes: In response to the wasp situation I found a neat little trick that I'll share with everyone. On my front porch the wasp was buzzing around to much for me so I put clear ammonia inside small candle holders and placed them around the porch - out of site of children or pets. They have taken the hint and aren't bothering me any more. Pat Pope
The Plant Man is here to help. Send your questions about trees, shrubs and landscaping to steve@landsteward.org or mail to: Steve Jones, "The Plant Man", P.O. Box 686, McMinnville, TN 37111. For resources and additional information, including archived columns.
