Ask a Master Gardener: Some pests are hard to spotSend gardening questions to firstname.lastname@example.org
Q: We planted two Chinese lanterns (physalis) last year. Something ate one of them completely and half the other one. This year, the surviving plant was about 5 inches high in mid-July when we noticed something was chewing the leaves. We didn’t see army worms or slugs. We put a 5-inch high aluminum cylinder around it and covered it with a piece of window screen, but it still got completely eaten up. What’s eating it, and if we try these plants again, how can we keep from losing them?
A: This is a bit puzzling. Chinese lanterns (physalis alkekenji) tend to be pretty pest-free. Occasionally they’re attacked by some of the pests that go after tomatoes and potatoes, such as potato beetles, but I think you would see those.
Flea beetles can go after nightshade family plants, too, and they are very small, so you might miss them. If the leaves had many tiny holes, they may be your culprits.
Some people report slug problems on physalis, particularly on young plants. Slugs are largely nocturnal, so gardeners often don’t see them and only see the damage they do. If the holes in leaves were larger, slugs are more likely than flea beetles.
The puzzle is how any pest would have gotten beyond your creative barrier. Perhaps they were already inside, hidden under leaves or buried in the soil.
What to do depends on what you’ve got. There’s information about slugs in home gardens at www1.extension.umn.edu/garden/insects/find/slugs/. There is information about flea beetles at www1.extension.umn.edu/garden/insects/find/flea-beetles/.
Q: My potato plants are bearing small, round fruits like little tomatoes. Is this a problem? Are they edible?
A: These are, in fact, potato fruits. Potatoes often don’t fruit, so the fruits sometimes surprise gardeners. They’re not a sign that your plant is in distress. “Potato berries” are related to tomatoes, but they are poisonous. Don’t eat them.