White and yellow sweetclovers are invasive species.
- Yellow and white sweetclover grow abundantly on disturbed lands, roadsides and abandoned fields.
- The plants degrade native grasslands by shading out sun-loving plants, reducing diversity.
White and yellow sweetclover should be reported. The Minnesota Department of Natural Resources provides detailed recommendations for reporting invasive species.
How to identify white and yellow sweetclover
- Biennial herbaceous plants; very fragrant.
- First-year plants do not bloom.
- Second-year plants grow three to eight feet high and are bush-like.
- Yellow sweetclover is usually shorter and blooms earlier than white sweetclover.
- Green (may have reddish tinge), grooved and generally hairless.
- Alternate, compound in groups of three, finely toothed, ovate, grayish-green leaflets, one inch long and three tenths inch wide.
- Middle leaflet grows on a short stalk.
- Small, white or yellow, floppy and tubular at base; broader toward outer edge.
- Five-petaled flowers are densely crowded at the top two to six inches along a central stem.
- Each flower is attached by a minute stalk.
- Larger plants can have numerous clusters of flowers.
- Blooms June through August.
- One or two small, hard seeds per flower.
- Seeds survive in the soil for 30 years.
- Strong taproot.
Reviewed in 2019