I saw my first Eastern Black Swallowtail butterfly the other day, and it immediately sent me running to my parsley bed to see if she had laid me any eggs. You see, most people grow herbs for cooking, but I tend to grow them mostly as host plants for butterflies.
Black Swallowtails (Papilio polyxenes) lay on parsley, dill, fennel, and rue, along with common roadside wildflowers like Queen Anne’s Lace (Daucus carota). This is one of the very easiest butterflies to lure to your own backyard, just by planting a bed of these herbs in a sunny spot. The eggs are lovely little pale green orbs, very easy to spot on the leaves of the herbs. The eggs hatch into tiny black caterpillars with a white stripe across the middle. You can see both eggs and newly-hatched caterpillars in the picture to the right.
The caterpillars of this species undergo many changes before they’re ready to pupate. These different phases are called “instars”. You can see the second through fifth instars of the Black Swallowtail in the pictures shown below. The process takes about two weeks from egg to chrysalis.
After spending a couple more weeks in chrysalis (remember, butterflies form a chrysalis, while moths form a cocoon), the butterfly emerges – and it’s always worth the wait.
Eastern Black Swallowtails are found throughout much of the U.S., including the entire Southeast. They closely resemble another common Southeastern species, the Spicebush Swallowtail. (Click here to learn how to tell the difference between the two.) Although they fly all summer long, in the deep South the herbs they use as host plants may struggle to grow in the sultry summer heat. Try keeping the herbs in partial shade and watering frequently to keep them alive and encourage Black Swallowtails to visit.
Do you grow herbs for Eastern Black Swallowtails? Tell us your tips and share your experiences in the comments below!
Every weekend, the Focus on Natives segment highlights a plant, bird, or butterfly native to the Southeastern U.S. Know of a particular species you’d like to see featured here? Make your suggestions in the comments section below.