White wingstem (Verbesina virginica), a.k.a. white crownbeard, a.k.a. frostweed, a.k.a. frostflower, is a native, fall-blooming, perennial wildflower. White wingstem blooms from Aug. through Oct. in Kentucky, and grows in medium to slightly moist, open woodlands and fields. It can reach over 5 feet tall.
Honey bees, native bees, and butterflies love both varieties of wingstem. Because it blooms so late in the season, white wingstem can provide a valuable last source of nectar and pollen before the killing frosts start. White wingstem is also a host plant for the silvery checkerspot (Chlosyne nycteis) caterpillar and the summer azure caterpillar (Celastrina neglecta).
White wingstem gets its common name of “wingstem” because it has long, leafy outgrowths running up and down its stem. The common names of “frostweed” or “frostflower” come from a characteristic that is observed on the first really cold nights of the year.
When the air temperature dips below freezing but the ground and plants haven’t frozen yet, frost flowers can form along the stem of white wingstem. Frost flowers aren’t flowers and aren’t made of frost. They occur when the sap in certain plants, such as white wingstem, starts to freeze. Since liquids expand as they freeze, the freezing sap splits the stem. The sap slowly leaks out the stem, freezing instantly as it hits the cold air and forming ribbons of ice known as frost flowers.
White wingstem is a good, late blooming, native plant to grow in pollinator gardens, but it can be aggressive in small settings. They are best grown in larger, less formal garden settings where their tendency to spread won’t create problems.
This article was part of Shannon’s original Kentucky Pollinators and Backyard Wildlife blog which evolved into the blog for Backyard Ecology. All of Shannon’s Kentucky Pollinators and Backyard Wildlife blogs can be found at https://shannontrimboli.com/posts/blog/.
Backyard Ecology: Creating Space for Pollinators and Wildlife
Nature isn’t just “out there.” It’s all around us, including right outside our doors. Hi, my name is Shannon Trimboli, and I am the host of Backyard Ecology. I live in southcentral Kentucky and am a wildlife biologist, educator, author, and owner of a nursery specializing in plants for pollinators and wildlife conservation. I started Backyard Ecology as a way to share my love of exploring nature and learning about different plants and animals. I invite you to join me as we ignite our curiosity and natural wonder, explore our yards and communities, and improve our local pollinator and wildlife habitat. Learn more or subscribe to my email list at www.backyardecology.net.