Sulfur cinquefoil

Sulfur cinquefoil is an herbaceous perennial in the Rosaceae (rose) family. It produces one to many erect stems from a woody rootstock. Stems may reach up to 3 feet tall and are thin, but sturdy, and are generally unbranched before flowers. Stems, underside of leaves, petioles, and calyx are covered with long, perpendicular hairs. Leaves are alternate, green, and sparsely hairy on the upper surface. Leaves are palmately compound, have serrated edges, and are 2 to 4 inches long. Sulfur cinquefoil flowers from late spring to mid-summer. Flowers are formed in loose, flat-topped inflorescences. Flowers consist of 5 pale yellow (sulfur-colored), heart-shaped petals that surround the hypanthium and numerous stamens and pistils, all of which are usually a darker yellow than the outer petals. Sulfur cinquefoil has a taproot and shallow lateral roots. Seeds are tiny, dark brown, and comma-shaped with light ridges or netting and narrow, winged margins.

There are several native species of cinquefoil in Teton County, and care should be taken to differentiate between the desirable native species and invasive sulfur cinquefoil.

Sulfur cinquefoil is native to Eurasia, and it was introduced to North America prior to 1900, though the timing and method of introduction are unknown. It creates dense stands and infestations through both seeds and vegetative reproduction from spreading lateral roots. New infestations are formed by the spreading of seeds. This species is frequently found in disturbed sites and rangeland.

Prevention and cultural control strategies should be utilized as much as possible.

There are no biological control agents currently available for sulfur cinquefoil.

Hand pulling and digging out of the entire root crown can be effective for new infestations. Mowing stimulates lateral root growth and is not recommended. Most livestock species will not graze sulfur cinquefoil due to the high tannin content. Goats may be utilized, but their effectiveness has not been well documented.

Large infestations can be controlled with herbicides. Spring treatments prevent flowering and seed production, and fall treatments may be effective at killing the root system. Read the label before using any herbicide. Contact TCWP if you have any questions about application rates or how to use an herbicide.

• Weed Report: Sulfur cinquefoil (2013) DiTomaso, J.M., Kyser, G.B., et al. Weed Control in Natural Areas in the Western United States. University of California Weed Research and Information Center.
• Best Management Practices: Sulfur cinquefoil (2005) King County Noxious Weed Control Program.
• Species Fact Sheet: Sulfur Cinquefoil (Potentilla recta) (2010) Reeves, K. National Park Service.
• Sulfur Cinquefoil Identification and Management (2019) Colorado Department of Agriculture Conservation Services.