Garden Q&A: Woolly bear weather forecasters and how to kill the grass
By Ellen Nibali
Dec 10, 2020 at 8:00 AM
This woolly bear caterpillar has almost no black stripe! Doesn’t that mean an easy winter?
The wider the orange band, the milder the winter — supposedly. Some studies seem to support this, showing a wide orange band correlating to mild temperatures about 70-80% of the time.
Perhaps this is because the orange band continues to widen as the caterpillar ages, and a temperate fall makes more growing possible. We find woolly bears later in the year than other caterpillars because, unlike most, they pass the winter not as pupae but as adults, nestled under leaves and debris. Antifreeze-like chemicals in their bodies prevent water turning into killing ice crystals. After warming up in spring and nibbling a leaf here and there, they turn into orange Isabella tiger moths.
If you find solid-orange caterpillars in the fall, however, don’t jump to conclusions. That’s the saltmarsh caterpillar. Nor does a solid black caterpillar (showing red/orange skin when it curls up) portend snowmagedden. That’s the giant woolly bear caterpillar, which becomes the appaloosa of caterpillars —the leopard moth. Neither predict weather. At any rate, a “mild” winter doesn’t necessarily mean no snow, just less severe cold. Don’t throw away the snow shovel.
We want to ditch the grass in the front yard of our new home. It’s perfect for a huge garden. What is the best method for killing grass? In our previous postage stamp garden, we just threw down cardboard, covered it in leaves and left it over the winter. We’d like to do the same here (lots of moving boxes!), but it is such a large area that we want to use mulched trees removed from another part of the yard. We heard that wood mulch doesn’t break down as quickly as leaves and can be more acidic/tannic for the soil. Can we use wood mulch and till it under next spring? Or are we looking at two years (at least) of “ugly front yard” if we cover our cardboard with wood mulch?
It sounds like you plan a vegetable garden. Fresh wood chips are not recommended for incorporation into vegetables gardens. Wood chips decompose much more slowly than leaves. Don’t till wood chips into the soil. Sawdust and, to a lesser extent, wood chips deplete soil nitrogen in the soil because their decomposition process uses nitrogen. It is okay to use fresh wood chips in permanent garden pathways or as a mulch in ornamental beds.
For a vegetable bed, cover with cardboard, compost and shredded leaves for spring planting. Wood mulch does not make soil acidic, however. Now is also a great time to get a soil test done for a new garden. Search “soil testing” on the Home and Garden Information Center website for the information you’ll need to take a sample, select a soil testing lab and understand the results.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland’s Gardening Experts” to send questions and photos.