Look before you cut because caterpillars are munching

Bronze fennel is a beautiful and airy plant that produces bright yellow umbrella-shaped flowers. It can also be an aggressive reseeder that creates plants with deep tap roots that are difficult to eradicate. The solution is cutting off the flowers before they go to seed.

It’s a job I have been meaning to do for a couple of weeks, and since the flowers are beautiful in bouquets it’s no hardship. But a close look at the plants — now towering to 6 feet tall — revealed that careful cutting is called for. Two large swallowtail caterpillars, so big they bent the stem they were feeding on, had taken up residence on the fennel.

Fennel, along with dill, parsley and golden alexanders (Zizia aurea) are all host plants for swallowtail butterflies. I grow all of those and enough of them to happily share with the future butterflies.

The caterpillars are on the hunt for food, so they’ll devour the foliage of their host plants. Monarch caterpillars can also be found now munching on milkweed, and don’t be surprised if you see the leaves of licorice plant (Helichrysum petiolatum) curling up into little taco-shaped pouches. This is the work of the American painted lady caterpillar, and it will only be a week to 10 days before the black, orange and white-spotted butterfly emerges from its chrysalis. Once it’s gone, the plant will respond well to a bit of pruning and will be beautiful again in no time.

There’s a lot of munching happening in the garden at this time of year, and not all of it is welcome. While caterpillars are busy working on becoming butterflies, other bugs will remain what they are — a menace.

Japanese beetles are probably at their plant-destroying peak right now. They love to attack roses and dahlias, among other flowers, but they happily take after the foliage on everything from beans and raspberries to Persicaria and lindens. Methods of controlling them ranges from covering plants with mesh, using organza bags over precious flowers, hand picking them into a cup of soapy water or spraying them.

But before you resort to that last option, think for a second about those caterpillars. Many of the products sold to control Japanese beetles will also affect, and possibly kill, those same caterpillars that we coddle in hopes of seeing the butterflies they will become.

Gardens can start to look tired in August. Gardeners can too, which is why it is an excellent time to focus on enjoying the little things, like a caterpillar happily eating away or the perverse joy that comes from drowning Japanese beetles in a soapy bath.