Finding Those Winter Garden Pests

Maritta Perry Grau
Frederick County Master Gardener

(2/3) Ah, February. Shortest month of the year (even though this year it’s 29 days); cold, wet, snowy. Surely, this is a month to set aside gardening chores and cuddle up under the afghan with a cup of tea or glass of wine and a good book. But no, bundle up and get ready for a mid-winter garden inspection tour.

Check for Vole Damage

Take a walk around your yard and check shrubs and even the lawn for vole damage. The University of Maryland Extension service notes that voles’ favorite munchies include Mugho pines, cherry laurels, azaleas, boxwoods, and junipers—all common in gardens and yards in this part of Maryland. Dead stems or branches and evidence of chewing on above-ground wood, crowns of plants that have been cut back, and on roots may indicate vole activity. In the lawn, you may see long, two-inch-wide tunnels or paths through the grass.

Voles are sometimes called "meadow" or "country" mice. Both voles and mice range from about five to eight inches long and have gray or brown fur. However, voles have much shorter tails (a mouse’s tail is about as long as its body), larger eyes, and smaller ears than mice.

How do you get rid of voles? Some web sites suggest spreading garlic, hot sauce, or hot peppers in the areas where you find evidence of the little creatures; using gravel instead of mulch; or using a vibrating or high-pitched sound device near their tunnels. You Tube features numerous ways to discourage voles; many university extension services offer advice; and of course, pest control companies have traps, poisons and baits.

Look for Scale Insects - While you’re on your mid-winter stroll, you’ll want to inspect trees and shrubs for overwintering scale insects, either armored or soft-scale, so named for their scaly or shell-like waxy covering.

What should you look for? The sap-feeding causes yellowed plant tissue, slower growth, and branch dieback. According to the Morton Arboretum, scale may be found on lower branches or new leaves of euonymus, bittersweet, pachysandra, or other hosts. "The male scale produces a small, thin, white covering and can be quite numerous on the undersides of leaves. The female scale lives under a gray or brown shell and is usually found on the branches. The female scale overwinters under its protective shell and deposits eggs in early spring under the scale covering," the web site states.

Soft-scale insects excrete excess plant sap as "honeydew," a sweet, sticky material that drips onto the foliage and branches below, and which often attracts ants, bees, wasps, and flies. Also, a dark fungus called black sooty mold can be found growing on the sweet honeydew. This fungus blackens roofs, porches, and any plant foliage where the honeydew is deposited.

Again, you’ll want to check with the extension services or on-line for appropriate treatment. Often a dormant oil spray works best, as it smothers the scale. Follow the directions and be sure that the trees or shrubs are in a dormant stage and that temperatures will be above freezing for at least 24 hours after you apply the spray.

Search out egg masses of destructive insects - Besides armored and soft brown scale, you’ll want to look for Eastern tent caterpillar, gypsy moth, and spotted lanternfly egg masses. According to the UMD extension service, the Eastern caterpillar egg masses look like black Styrofoam and are most often found on the ends of cherry and crabapple tree branches. Gypsy moth egg masses, emerging from underneath tree bark, are covered with tan or buff-colored hairs, looking like stiff pine needles layered all over the cocoon. The egg mass is usually about 1 ½ inches long, about ¾ of an inch wide. Spotted lanternfly egg masses, the most recent invasive and destructive insect to breach Maryland’s borders, look like "unevenly spread [mud-like, gray] mortar smeared on almost any outdoor surface," according to farmanddairy.com. If you find any, scrape them off into a bag and saturate the mass with hand sanitizer or rubbing alcohol.

Now that you have those tasks out of the way, check the University of Maryland’s February list for some great hints on and links to seed-starting, planting spring bulbs, developing raised garden beds or container gardens, and caring for indoor houseplants. You have lots to keep you busy inside and outside before you start the spring chores of March.

Read other articles about controlling insects & garden pests