One Blue Butterfly Bush will be left outside to test its hardiness for our Zone 7. Some Zone 8-9 gardeners say it will freeze back to the ground, but roots survive and send up new stems in the spring.

Individual flowers of the blue butterfly plant are small with pale blue lobes with a single darker lobe. The prominent stamens and pistil resemble a butterfly’s antennae. Gary Bachman I MSU ...

Other plants, such as the aptly-named butterfly bush produce flowers that attract plenty of species of pollinator, but don't support the entire lifecycle of butterflies.

The desired result is the plants would fully bloom in two years and be supporting the Karner blue butterfly population, Wilder said. The seeding is done in narrow sections about 20-by-3 meters each.