Q:
Butterfly houses make attractive ornaments, but how useful are they in bringing butterflies to the garden?
Mike Taylor, Cedar Rapids, IA
A:
Jaret C. Daniels, Ph.D., curator of butterflies at the Butterfly Kingdom Conservatory in Hilton Head, South Carolina, responds: Designed to provide shelter for hibernating adult butterflies from inclement weather or cold temperatures, butterfly houses have become familiar garden accessories. These structures resemble birdhouses, but they are equipped with elongated slits instead of round holes for entry. Most have a hinged door or removable lid so that bits of branches or twigs can be added for adult butterflies to wedge between or grab hold of. When fully stocked, butterfly houses are hung or mounted on a pole in the garden with hopes that butterflies will make their way inside.
While the premise sounds believable, gardeners become perplexed when they fail to see any butterflies actively occupying these cozy homes. They are often convinced that they put it in the wrong place or failed to add the right ingredients. In reality, butterfly houses aren’t effective at attracting butterflies to a garden. And even if they did work, butterflies would not come knocking during the summer.
Although there are a number of butterfly species, like the mourning cloak (Nymphalis antiopa), that survive the winter months as adults, even in cold northern climates, they prefer to hibernate in the old-fashioned places: under bark, in vegetation, or in a brush pile. To a butterfly, these natural areas are more inviting and protective than an artificial structure placed out in the open.
That is not to say that gardeners can’t help butterflies or other wildlife. Butterfly houses provide great hiding places and nest locations for spiders and wasps, two very beneficial garden allies. Planting a diversity of colorful native flowers and larval host plants, as well as leaving shrubby areas or brush piles, also helps. By doing so, your garden can provide food and shelter for birds, butterflies, and other desirable wild creatures and remain an attractive destination year-round. In the meantime just sit back, enjoy nature, and consider that butterfly house as only an attractive garden ornament.