Weed of the Month: Sulfur Cinquefoil

For this Weed of the Month, we’re calling out the black sheep of the cinquefoil family: the sulfur cinquefoil. Though there are desirable native cinquefoil species, the sulfur cinquefoil is a tenacious invader—it can push out native plants and even other invasive species! Luckily, we’ll help you come out on top.

Origins 

Sulfur cinquefoil (Potentilla recta L.) is native to Eurasia, and came to North America sometime before 1900. Thanks to its hearty nature, it spread quickly, and can be found throughout most of the US, especially in the Midwest, Northeast, and Northwest. 

Plant Description

Sulfur cinquefoil is an herbaceous perennial in the Rosaceae (rose) family. Stems are thin and sturdy, reaching up to 3 feet fall. Most of the plant is covered with long, perpendicular hairs. The alternating green leaves are sparsely hairy and serrated.

Sulfur cinquefoil flowers from late spring to mid-summer with 5 pale yellow, heart-shaped petals that surround a darker yellow hypanthium, stamens and pistils in the center. It has a taproot with shallow lateral roots surrounding it, and the seeds are small, brown, and comma shaped with light netlike ridges and narrow, winged margins.

Thanks to its high tannin count, most livestock avoid eating it. This, plus its aggressive growth, means it can outcompete native plantlife and reduce the foraging value of pastures. 

There are several desirable species of cinquefoil, so take care to properly identify the invasive variant before removal.

Habitat

Sulfur cinquefoil can be found far and wide in North America. It’s found frequently in dense strands in disturbed areas, rangeland, abandoned fields, pastures, waste fields and more. 

Sulfur Cinquefoil Growth

Sulfur cinquefoil grows quickly, creating thick growths though both seeds and vegetative reproduction through the lateral roots. New infestations can occur by seeds spread by clothing, tires, animals, and more. Seeds can live in the soil for over 4 years, and the plants have a lifespan of 20.

Sulfur Cinquefoil Management

Eliminating sulfur cinquefoil is important to keep pastures nutritious and to encourage biodiversity. Before tackling an infestation, make sure you properly identify the sulfur cinquefoil.

Prevention and cultural control methods are the best first step, like hand pulling the root crown on new infestations. Mowing isn’t recommended, as it can stimulate root growth. However, goats may be a good alternative, though it’s not well tested. Unfortunately, no biological control agents exist (besides goats, maybe).

For large infestations, herbicides are an effective option. Spring treatments prevent flowering and seed production, while a fall treatment kills the root system. Contact TCWP if you have any questions about application rates or how to use an herbicide.