While caterpillars might help themselves to quite a bit in your garden, it’s good to know which kind you have as that will dictate how to mitigate the damage. For the most part, two main types of caterpillars can be pests in your summer garden.
If you’re noticing damage on leaves of plants and trees, the first group to look for is the Lepidoptera caterpillars. These caterpillars are the larval stage of butterflies and moths. Cabbage worms, tomato horn worms, tent caterpillars, spongy moths, any of the swallowtail and monarch butterflies belong to this family.
The Lepidoptera family of caterpillars tend to be big with small hairs, and they tend to do a lot of damage, usually individually, as opposed to en masse in your garden.
These caterpillars can usually be controlled by hand-picking, or using a common organic spray, like BT or Bacillus-thuringiensis.
The other group of caterpillars to check for is in the Hymenoptera family. These small caterpillar larva do not become a moth or butterfly but instead, an insect called a sawfly.
Sawfly caterpillars are small and smooth and their color can range from translucent to yellow, green or black. They tend to eat in groups, and when you get too close to them, they’ll rear up on their hind legs! (No worries, they aren’t harmful.)
Sawfly larvae will eat a whole bunch of different plants from birch, willow, dogwood, pears, columbine, pine, roses, azaelas and more! The caterpillars can eat all the needles on a pine, for example, or defoliate plant and tree leaves. Depending upon the sawfly, the damage will be different.
Sawfly controls are different than ones used to mitigate Lepidoptera; BT doesn’t work on them. Try hand-picking the caterpillars off your plants and shrubs or — in the evening, so as not to harm the bees — spray Spinosad or neem oil.
Rock hard potatoes
Q: We harvested our garlic this weekend, along with several volunteer potato plants. We were excited to roast them up this weekend, as usual, with olive oil, salt and pepper, and we cut them small to cook quickly, but after nearly an hour in the oven, these taters were nowhere near done. I finally turned the oven off and left them in there for a couple of hours, but they never got soft. What gives? – Jo and Gus, in Springfield
A: The answer for this one comes from the Idaho Potato Commission: potatoes that won’t soften, even after boiling and cooking for a long time, might have had cold-weather exposure.
Starchy potato varieties or more susceptible to this, so to avoid it from happening again, start with certified disease-free seed potatoes and choose ones that are less starchy.
Lettuce crop won’t take
Q: I’ve always been able to grow multiple crops of lettuce throughout the growing season. I had a good first crop this spring, but I’ve been unable to get any of my lettuce to germinate. After that, I’ve tried different areas of the garden without success. Could the wet weather be the problem? – Fran, in Richmond
A: The hot, humid and wet weather is probably the problem with the lettuce, which prefers cool weather.
Don’t give up, though! The weather is shifting and you could start the seeds in small pots and then transplant the seedlings into the garden for an early fall crop.
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