This time of year, I frequently notice orange caterpillars on my passion flower vines. Do you have them, too, and wonder what they are?

About those caterpillars

There are several butterflies that use passion flowers as host plants: Gulf fritillaries, red-banded hairstreaks, zebra longwings, crimson-patched longwings, and Julia butterflies.  Also, I’ve seen pictures of variegated fritillary caterpillars on passion flowers, so they probably use them, too.

Gulf fritillary caterpillar

If you live outside of Florida or south Texas, you’re likely seeing Gulf fritillary caterpillars on your passion vines. (Red-banded hairstreak caterpillars are very small. You may notice them less compared to the giant orange caterpillar doing obvious damage to your plant.) Gulf fritillaries are beautiful, large, orange butterflies. I look forward to seeing them in my yard every year. I hope you do, too.

Gulf fritillaries

About passion flowers

If you don’t already have passion flowers, let me tell you about them. Passion flowers are also known as Passiflora or passion vines. They look so exotic, and I was afraid I wouldn’t be able to keep them alive. Well, I was silly. It turns out that some passion flowers are remarkably hardy and easy to grow, as long as they aren’t planted some place approximating either a desert or a tundra. I say that somewhat tongue-in-cheek. However, I’ve also had them take over entire fences despite half-hearted attempts to keep them in check.

A Passiflora variety

Passiflora incarnata, sometimes called Maypop, is a variety native to the eastern U.S. It is hardy from zones 7–11 and needs full to part sun. I haven’t been able to kill it, yet, despite neglect, drought, and heat. Other cultivars (and there are many) are very hardy, as well. Many pollinators and hummingbirds use them. Maypops and other Passiflora are great additions to any garden. Plant them, and the fritillaries will come.