From left to right, Sulfur cinquefoil plant, Sulfur cinquefoil flower head (Gary Stone Photos)
Sulfur cinquefoil – invasive species in western Nebraska
By Gary Stone, Extension Educator, Panhandle R&E Center, Scottsbluff
Early Detection and Rapid Response (EDRR) is a concept to identify potential invasive species prior to or just as the establishment of the invasive is taking place. An integrated pest management plan (IPM) can be developed to manage, contain and eradicate the invasive species before it can spread further. This will avoid costly, long-term control efforts.
Sulfur cinquefoil is a perennial forb that has been identified in parts of Nebraska. It is either a state or local noxious weed in Colorado, Wyoming and other western states.
Also known as rough-fruit cinquefoil, five-finger cinquefoil, or erect cinquefoil, sulfur cinquefoil’s scientific name is Potentilla recta L. It is of the Rosaceae (rose) family.
Originally from Europe and the eastern Mediterranean, sulfur cinquefoil was first reported in North America in the early 1900s, and is distributed across the United States and Canada.
Sulfur cinquefoil is an herbaceous perennial forb. It reproduces and spreads primarily from seed. Sulfur cinquefoil is a prolific seed producer. Seeds can remain viable in the soil for more than four years. Mature plants can live for 20 years or more. Sulfur cinquefoil is one of the first plants to green up in the spring and can remain green into the fall if adequate moisture is available.
Sulfur cinquefoil has a taproot, which dies back after a freeze. Regrowth from the roots may produce several erect stems 1 to 3 feet tall. Leaves are composed of 5 to 7 toothed leaflets that radiate from a common point. Long, stiff hairs extend outward from the stems at right angles. Flowers are pale yellow / sulfur-colored with five heart-shaped petals produced at the end of the stems in June and July. Each flower produces hundreds of seeds, which can be scattered by water, wind, animals and hay.
Sulfur cinquefoil can be found in any type of habitat but normally establishes quickly in disturbed areas and over-grazed sites. It can also invade healthy, undisturbed sites as well, out-competing desirable forbs and grasses in pastures and rangeland and reducing biodiversity. Sulfur cinquefoil is very aggressive and is known to out-compete other invasive plants.
Sulfur cinquefoil has no forage value for livestock and contains high amounts of tannins, which can interfere with the digestive process. Wildlife have been observed to graze on the seed heads in the fall.
Prevention is the best and cheapest management option. Having well-established grasses and forbs on a maintained pasture or rangeland with proper grazing and rotational grazing techniques can go a long way to prevent its establishment. Scouting, monitoring and proper identification are key factors for management. Infestations of this weed can occur very rapidly.
Because Sulfur cinquefoil is related to strawberries, and there are a number of native cinquefoils, there are no biological control methods available at this time, other than grazing with sheep or goats that can reduce seed production and seed viability.
Pulling or digging up the plants below the crown is effective if there are a few plants. Mowing is not a viable option.
There are numerous chemical treatment options available to manage Sulfur cinquefoil. Products containing aminopyralid, clopyralid, chlorsulfuron, dicamba, metsulfuron, picloram, triclopyr, glyphosate (non-selective) and 2,4-D have been shown to work. 2,4-D will only suppress plant growth. Products with residual may do better.
Spring or fall applications, especially in the rosette stage, prior to pre-bud stage, are best. The addition of a non-ionic surfactant to the herbicide mix will aid in control. Re-treatment is usually necessary in 3 to 5 years.
(Be sure to select a product labeled for the site. Read, understand and follow all label instructions when using any pesticide. Confirm the identification of Sulfur cinquefoil before herbicide application to avoid treating native species.)
This article is based on information from these sources:
Frost, R., “Featured Weed: Sulfur Cinquefoil”, Big Sky Small Acres, Montana State University, Winter 2010
Kadrmas, T. et al, “Identifying and Managing Sulfur Cinquefoil”, University of Nevada, Fact Sheet 03-04
“Sulfur Cinquefoil”, Washington State University, Island County Noxious Weed Program Weed Alert
USDA / NRCS Plant Profile, “Sulfur Cinquefoil, Potentilla recta L.”