Tuesday, September 9, 2014


I have previously tried to grow a Passiflora arida (Baja passion flower) from seed, but I was unsuccessful. Aside from wanting the plant itself, I wanted to attract Gulf Fritillary butterflies. They use various species of Passiflora as a host plant, meaning that they lay their eggs on the plant and the caterpillars eat it. Most butterflies will go to any flower for nectar but they will use plants from only a selected family, genus or species as their host. In the absence of a P. arida I decided to just go to the nearest nursery and buy a passion flower. Below is the plant I bought and a good view of the flower. Most passion flowers are vines. I planted this one in a container and started training it up a post.

I don't know what species/variety it is and I don't care. I just wanted something to attract the butterflies. It worked immediately. In the photo above you can see that some of the leaves have already been chewed. The Gulf Fritillary butterflies found it right away and started laying eggs on it. Below is the butterfly in the process of egg laying.

Sometimes there would be several butterflies on the vine at the same time. Soon the eggs hatched and the caterpillars became large enough to be readily visible.

The vine grew rapidly, but the egg laying and caterpillar chewing of the leaves was even more rapid. Soon the caterpillars had entirely stripped the vine of leaves. That's okay with me because I want the butterflies, not the plant. The plant is still alive, though leafless, and dozens of butterflies still come around every day. The plant must put out a chemical signal that attracts them, even the bare stem.

Now the caterpillars have been replaced by cocoons. They are everywhere in the vicinity of the plant. They resemble a dried leaf, which is excellent camouflage. Also, passion flowers contain a chemical which is ingested by the caterpillars and makes the adult butterflies somewhat toxic to birds and other predators. This mechanism is very similar to the relationship between Monarchs and Milkweeds.


  1. We also have passionflower vine in our Encinitas garden, planted more than a half dozen years ago. When we planted two vines on either side of a cheap cedar trellis arch from Target's garden clearance, we had no idea it was a Gulf Fritillary butterfly magnet. The butterflies quickly found the two vines planted on either side of the arch and devoured everything but the vine stems, much like your vine. I didn't know this passiflora was a Baja native, though. I'm very happy to learn that, so thank you.

    It was serendipitous that our planting location was in the "utility" area of the garden rather than in the more prominent public location I'd originally considered, because the vine is quite raggedy for some time after the caterpillars have multiplied and commenced their feast. After the breeding season is over the leaf-less vine eventually does does re-leaf, but IMO it's more than a little unsightly. But like you, we are happy to be the dinner hosts. The sight of the dozens of orange butterflies fluttering around the garden is an annual reminder that our garden isn't just for our own pleasure.

    Despite the annual caterpillar feast, our vines grow back vigorously year after year without any help from us except a little water where the original vines were planted. The good aspect of its vigor is the vine now has extended to a nearby lean-to potting bench area constructed of lattice panels, which is just fine with us. However, being a vine, it doesn't recognize boundaries. Countless vine sprouts pop up all over that side of our garden (even many, many yards away), so I'd also say this vine does have a strong tendency toward "weedishness". If that's an issue, it can be kept in check by pulling up the new sprouts regularly. When allowed to sprout out of control its tempting to nickname it "Kudzu". ;-)

    1. I'm so glad to hear that your passiflora survived after being stripped bare by the caterpillars. Maybe mine has a chance as well. Right now it doesn't look like it could last another day, and yet the butterflies keep coming around. I think I misled you on one point - not all passifloras are from Baja. Only a couple of species are native there. The rest are from other tropical parts of the world. I really wanted to grow one of the Baja species but it died before the butterflies even found it. Thanks for commenting!