How to make butterflies happy

If you plant it, they will come. Growing the right host plant will attract particular butterflies and feed their hungry caterpillars.

This is National Pollinator Week and butterflies rank among the most beloved of beneficial insects.

In fact, swallowtail butterflies have been named the official Pollinator of the Year by the Pollinator Partnership, the group that coordinates Pollinator Week.

“Swallowtail butterflies are among the most striking and recognizable butterflies in the world,” says the partnership, noting about 30 swallowtail species are native to North America. “With their large wings, bold patterns and graceful flight, they’re a favorite of gardeners and naturalists alike.”

Those “tails” on the end of their wings aren’t just cute; they’re a defense mechanism, says the partnership. Birds and other predators often strike those little wing extensions first, allowing the butterfly to escape.

Many flowers provide nectar to adult butterflies. They prefer wide-open blooms that offer a landing spot as well as the sweet stuff. (Unlike hummingbirds, butterflies can’t feed while hovering.) Think coneflowers (Echinacea) or native buckwheats. Other favorite flowers include thistles, sages, lavenders, California lilacs, catmint, lantana, anise and, of course, butterfly bush.

But when it comes to host plants, butterflies get very picky. They demand specific plants to feed their young.

Monarchs are well known for their love of milkweed, particularly native milkweeds (Asclepias speciosa or fascicularis). The flowers feed the adults, but it's the foliage that feeds the striped caterpillars.

Likewise, pipevine swallowtails gravitate to the California pipevine, which is native to river and stream banks in the Sacramento Valley. Also called Dutchman’s pipe (for its distinctive curved flowers), this is the only host plant for pipevine swallowtails; no pipevines, no pipevine swallowtails. That’s why it’s crucial for suburban gardens to incorporate this interesting native perennial.

Sacramento’s other common swallowtail – the Western tiger swallowtail – has a much wider range of host plants: Willow, cottonwood, alder, aspen, ash and chokecherry.

According to the Butterflies and Moths of North America (another citizen science project), 1,430 different species of these important pollinators have been recorded in California. Of those, about a dozen are common to the greater Sacramento area.

Not so common but among the showiest butterflies is the Gulf fritillary. Originally from the Gulf States, this large, orange butterfly has colonized in several California communities including parts of Sacramento. The key to their appearance: Passionflowers. Gulf fritillaries must have passionflower vines for their caterpillar nurseries. (But they’re even picky about passionflowers; not all species of Passiflora will do.)