Patches of my thyme have been dying off for weeks. Now I see webbing in the thyme.

Spider mites?

The webs are not from spider mites. Thyme is prone to a fungus known as Rhizoctonia web blight.

Web blight is common and infects nearly all herbaceous perennials, especially in hot, humid conditions. It does not kill roots.

To control it, sanitation is important. Remove all the infected above-ground growth. Thin plants to improve air circulation.

Do not water in hot, humid conditions. Dead areas should come back next year. This disease is similar to Southern blight. Both can be searched on the HGIC website.

?

I raise tomatoes in raised beds. I use hardware cloth fencing topped with bird netting to keep out vermin. This year something eats a 2-by-1-inch hole in every tomato just as it becomes ripe and finishes it off in two days. Fruits two feet off the ground are just as vulnerable as low fruit. Whatever this is shuns yellow tomatoes. What do you think is causing this?

Even though your plants are caged and netted, squirrels may be getting in. Squirrels bite tomatoes and even stockpile them in the corners of gardens. Preventing squirrel damage is difficult if you have mature trees nearby. Wildlife tends to feed more heavily on vegetable crops during dry spells. Consider putting out a container of water for the wildlife.

Pick fruit at the blush stage, and let tomatoes ripen on your countertop. Flavor should still be good. Also, try sprinkling your tomatoes lightly with ground lime, so the critter gets a mouthful of lime with each bite. Reapply after rain. Lime washes off easily after you pick.

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.

Digging deeper

Beautiful wood nymph

Eudryas grata

This creature lives to confuse. Is it a slug? A snail? No, it's a moth trying to look like bird droppings. At rest, it folds its wings together and splays out its long downy forelegs to mimic dribbles of grayish white. The nocturnal moths are attracted to light, where their subtle colors might be glimpsed. The smaller back wings are a pale yellow. The larger white wings are marked with red, black and olive green. Whereas the moth tries to fool its predators, its larval stage uses bright color to warn predators to leave it alone. On the caterpillar, flashy orange bands with black dots alternate with thinner bands of black and white. Feeding on grapevines, Virginia creeper and buttonbush, beautiful wood nymph caterpillars are often found near the edge of woods.

— Ellen Nibali