It’s so delightful when a lovely butterfly (is there any other kind?) floats into our yard. Each year, as soon as June rolls around, I catch glimpses of gorgeous Western tiger swallowtails and orangey Painted ladies flitting here and there, as well as the occasional Mourning Cloak in the vicinity of our octogenarian American elm tree, one of its host plants. This summer I’ve noticed, for the first time, a Red Admiral butterfly (Vanessa atalanta) gliding in now and then. This species is reportedly rather territorial and will stay in one area for days or even weeks, so I hope to see her again. She’s apparently attracted to the heat radiating from the rocks on the west-facing side of our veggie garden, as well as the white trellis that supports our cucumber plants, and this morning she surprised me by landing on the white shirt I was wearing. She was near some native wallflower plants (Erysimum capitatum) growing nearby, but I’m not certain she used it.
Red admirals aren’t very fussy about habitat, but for food they prefer sap from trees, fermented fruit, and bird droppings—yes, you read that right—from which they obtain nutrients, such as amino acids and salts that are necessary physiologically, behaviorally, and ecologically. Many butterfly species and some other insects consume droppings as well, and don’t get me started on the fascinating spider that masquerades as bird poop to hide from predators. Flower nectar is a actually a second choice for red admirals, who only forage at flowers—such as aster, milkweed, penstemon, fireweed and wallflower—when sap, fruit, and droppings aren’t available.
But as you may know, butterflies need much more than food to survive and reproduce; they also need plants on which they can lay their eggs. These can’t be just any old plants; they need to be the kind that their larvae can feed on (as their ancestors have done for millennia) as they grow into pupa (chrysalis), that awkward metamorphic stage before adulthood. Some butterflies aren’t terribly picky and may be able to lay their eggs on four or five different plant species, but others, like monarchs and red admirals, can use only one species.
My butterfly reference tells me that red admirals lay their eggs only on plants of the nettle family (Urtica spp.), something I’ve never grown. Uh-oh. As I began pondering where the heck in my yard I could grow it, I suddenly remembered a wonderful nettle soup that I had at an equally wonderful villa on the west coast of Sweden some years back. It’s edible and one of those “super foods” that are extremely rich in nutrients and purportedly very cleansing.
So now I’m on a mission to grow some native stinging nettle (Urtica dioica)—a bit for us to eat, but mostly for the butterflies. It turns out that the Satyr comma butterfly also uses only nettle as a host plant, although they are reportedly rather rare in parts of their range and it’s highly unlikely I’ll ever see one in my urban yard. I prefer to grow it myself, so that the wild stuff in wilder places can be left to the butterflies. But first I’ll have to carefully figure out where to plant it … and buy some stinger-proof gloves. Or maybe I should just stick with providing for species that don’t need such outrageously prickly plants.