Frostweed is a North American native
Frostweed, Verbesina virginica is an impressive plant that blooms with pretty white flowers in late summer. The tall plants with rough, grayish-green leaves thrive at the edges of moist woods and sunny meadows. The flowers appear in flat groupings called umbels at the tops of the plants. These members of the vast Asteraceae family can reach over eight feet tall in favorable conditions and the flowers are magnets for most flying pollen and nectar eating insects at this time of year. Native to the southeastern U.S. And the Midwest through mid-Missouri and mid-Illinois, this biennial plant forms thick colonies where conditions are favorable. It has several other common names, so you may hear it called, crown beard, ice plant, Indian tobacco or wingstem too. The unique wings that grow along the stems are shown in the image below.
Ancient uses of frostweed
This plant was well-known to the native peoples and a part of their herbal pharmacy. It was often used as a diuretic and laxative. (It is amazing how many laxative plants there were in those days!) The tea was also an eyewash and used to treat arthritis and kidney stones. The Choctaw called it Hohshish okwa stikbe ishkwo and pounded the roots to a pulp and soaked them in water. They used the resulting liquid as a fever reducer. The Chickasaw used the liquid as a topical cure for venereal diseases. I do not find any evidence that this plant was used as a natural dye or a food source. They did dry the leaves and smoke them as a tobacco substitute and it was also smoked ceremonially.
How frostweed gets its name
The most interesting aspect of the frostweed is what happens when the first hard freeze hits. There are wing-like growths that appear during the summer along the main stems of the plant and these split open during that first freeze and the sap inside the plant seeps out, forming lovely, natural ice sculptures and ribbons. Often called frost flowers, the ice can be four to six inches across and while they are mostly found at the base of the plants, ice flowers forming further up the stems are not unheard of. You have to get up early to see them because as the morning temperature rises, the pretty ice sculptures quickly melt.
Where frostweed grows best
This is mainly a plant for the wild things, although Bambi doesn't care for the bitter foliage, so if deer are a problem, this might be a good choice. Its main use is for much needed late summer food for migrating monarchs and a pollen source for our bees. This time of year, pickings are slim for food and many species of insects are often seen crowded on top of the flowers gathering nectar and pollen on sunny days. However, this isn't a plant for a formal garden. They can grow quite tall and gangly and the fibrous roots tend to form dense mats. You can control the height a bit by cutting frostweeds back by half in late June, but most gardeners just let them grow. The colony I found was by the wooded bank of a spring-fed creek near my home. Goldenrod, ironweed, Desmodium and other late summer flowers were blooming along with the frostweed where the bush hog couldn't reach and the area was alive with insects. If all farms would leave a wild space for the native plants, our fragile pollinators would have a better chance at surviving.
Growing frostweed in your garden
Growing frostweed isn't all that hard and it is a great addition to a butterfly and pollinator garden. Just remember that this plant is tall and decidedly weedy. It needs to be placed at the back of the garden so it won't hide smaller and shorter plants. It thrives in most soils, however a neutral soil of average fertility is best. Plant seeds where they are to grow after the last frost and make sure that the area doesn't suffer from drought. Thin the little plants to about eight inches apart and let them grow throughout the summer. There is conflicting information as to whether this plant is a biennial or a perennial, even the USDA site lists it as both. A biennial does not bloom in its first season, blooming in its second year and then dying. Since frostweed produces so many seeds, it is possible that there are always new plants maturing and it seems like a regular long-lived perennial. Personally, I'd make sure that some of the seeds mature and fall to the ground each season to ensure more plants. Frostweeds do best in partial shade. The colony I found gets late afternoon sun and the butterflies dance around the flowers in clouds then. This is truly a wonderful pollinator and butterfly plant and it deserves a place in any natural or prairie garden.