October Weed of the Month: Red Hailstone

Red hailstone (Thladiantha dubia) is an herbaceous vine named for the red fruit on female plants. The vines grow vigorously to climb over other vegetation enabling red hailstone to dominate. It smothers native vegetation and has been problematic in agricultural fields.

Within the United States, red hailstone has been found in Illinois, Massachusetts, Michigan, Minnesota, New Hampshire, New York, and Wisconsin. Minnesota infestations are in Linwood (Anoka County), Watertown (Carver County), Fergus Falls (Otter Tail County), Orrock Township (Sherburn County), and Stillwater (Washington County). Native to Asia, the vines may have been planted here as a vegetable or ornamental; then the vines spread.

Red hailstone is an attractive vine with separate male and female plants that can grow in light levels ranging from full sun to shade. To date, all populations reported in Minnesota are male, so there has not been reproduction by seed. However, the vines spread by underground stems and produce tubers that can send up new shoots. The vines die back to the ground each winter but can grow 18 feet per year to cover large areas. Leaves are alternate, simple, and heart-shaped with irregularly toothed edges.

This vine is also known as goldencreeper for the golden flowers. Flowering is from July to September. Flowers have five petals fused at the base to form a tube. Curling tendrils attached to the stems help the vines to climb. University of Wisconsin Extension produced this helpful identification video "Goldencreeper (Thladiantha dubia): A listed invasive plant in Wisconsin."

If you find red hailstone in Minnesota, please report it to Arrest The Pest using our new online reporting form or note the location and email photos of the leaves, flowers, and infestation to arrest.the.pest@state.mn.us.