URBANA, Ill. – University of Illinois Extension encourages gardeners to take their butterfly garden to the next level. Kelly Allsup, Extension horticulture educator, says the project can be challenging and rewarding.
“Chose the right plants and, with some care, caterpillars are feasting, adding to the diversity of backyard and enhancing healthy pollinator habitats,” Allsup says.
The most common caterpillar food sources in gardens are milkweeds for monarchs and parsley for black swallowtails. By adding a few more native shrubs, perennials, annuals, and weeds, a caterpillar café could be open in no time, Allsup says.
Shrubs
Blackhaw viburnum: Boasting stunning white flowers in late spring, this deciduous shrub grows 12- to 15-feet tall in full sun to part shade. These flowers turn into blue drupes that persist into winter and become bird food. The blue drupes contrast nicely with the red fall foliage. Spring azures, Baltimore checkerspots, and clear wing hummingbird moth caterpillars will populate this plant.
Leadplant: A native shrub with dissected gray leaves and hairy stems, the leadplant's summer flowers are dense spikes with bluish-purple blooms that are enjoyed by butterflies. Grown in full sun, the plant reaches and spreads 2 to 3 feet. The leaves are munched on by southern dogface caterpillar.
Spice bush: Growing between 6 to 12 feet in full sun or part shade, this native deciduous shrub is dioecious which means there are separate male and female plants. The female plants bear red drupes after being cross-pollinated by a male plant. The flowers appear before the leaves and are bright yellow and fragrant. After the leaves are consumed by spicebush swallowtail caterpillars, they turn yellow in the fall. The leaves have a unique fragrance when crushed.
Annuals
Snapdragons: These cool-season annuals have been selected by the industry to weather the summer heat. They make great additions to any garden or pot that gives them full sun. They grow about 1 to 2 feet tall and come in a plethora of colors. The blooms may attract the butterflies and hummingbirds, but they serve as a food source for buckeye caterpillar.
Sunflowers: One may start sunflowers from seeds for summer-time blooms. Thriving on full sun, sunflowers can reach 3 to 10 feet depending on the type. "A plant coveted by most birds usually doesn’t have the most attractive leaves by the end of the season, so let the caterpillars of gorge on checkerspot or silvery checkerspot," Allsup says.
Perennials
Purple coneflower: A gardener’s favorite, coneflower is an easy-to-grow native plant. Grown in full sun, it usually looks attractive during the season, unless large groups of silvery checkerspot begin eating the leaves. These durable plants will send up leaves and the most beautiful long-lasting blooms, Allsup says.
Weeds: Usually detested by those who want the perfect lawn, clover, violets, and plantains are early sources of bee food. These unwanted plants may also be munched on by clouded sulphur and buckeye caterpillars.
Groupings of these six plants can attract the black and brown spiky silvery checkerspot caterpillar; green, black, and yellow striped southern dogface caterpillar; orange and black with flecks of blue iridescent buckeye caterpillar; and the bright green to yellow snake looking caterpillar of spicebush swallowtail, Allsup says.
"The butterfly garden in my backyard will benefit the ecosystem for caterpillars of the butterflies,” Allsup says.
University of Illinois Extension is the flagship outreach effort of the University of Illinois at Urbana-Champaign, offering educational programs to residents of all of Illinois' 102 counties and far beyond. Illinois Extension provides practical education you can trust to help people, businesses, and communities solve problems, develop skills, and build a better future. Through our Agriculture and Natural Resources programs, Illinois Extension supports the economic viability and environmental sustainability of natural and managed landscapes and productive lands in Illinois. Horticulture program educators provide research-based information and training about gardening, fruits and vegetables, flowers, insects and diseases, composting, landscaping, and more.
News source/writer: Kelly Allsup, Horticulture Educator, Illinois Extension