Identification and Reproduction

Identification: 

• Sulphur cinquefoil is a perennial herb that grows from a woody taproot. 
• Stems are erect and can reach up to 80 cm tall. The upper portion of the stem is branched and covered in hairs. 
• Leaves are arranged alternately and attach to the stem on stalks. Leaves are palmate and divided into 6 or 7 individual leaflets. Each leaflet has toothed edges. Leaves decrease in size moving up the stem. 

• Flowers will be found at the end of stems. Flowers are yellow and composed of 5 heart-shaped petals and 5 hairy green sepals. 

Reproduction: 

• Reproduces by seed and vegetatively. 
• Seeds can remain viable for up to 3 years. 
• A single plant can produce over 1,600 seeds in a growing season. 
• New shoots will emerge and spread from the woody root crown. 

Habitat & Ecology

• Prefers partial to full sun exposure. 
• Invades rocky or low-nutrient soils. 
• Commonly found on pastures, fields, vacant lots, roadsides, railroads and other disturbed sites. 

Impacts

Social: 

• Has an unpleasant taste to livestock. 
• Its presence on pastures will decrease forage opportunities for grazers. 

Ecological: 

• Decreases plant biodiverstiy. 
• Will disrupt natural food web by decreasing forage for wildlife. 

Management

Mechanical Control: 

• Hand pulling can be effective on small infestations. Ensure that at least the first few inches of the root system is removed. 
• Pulling and digging should be completed prior to seed set. 
• Refrain from mowing plants as this will encourage growth and spread plant parts that will reestablish. 
• Cultivation of the soil and then reseeding with grass species has been successful for larger populations. 

Chemical Control:

• Herbicide treatments should be applied during the growing seasons; spring and early summer. 
• Currently picloram, 2,4-D and aminopyralid are registered for use on sulphur cinquefoil. 
• Please carefully read herbicide labels prior to application. 

Resources

Download A Guide to Weeds in British Columbia for Sulphur Cinquefoil here.

Header photo (Matt Lavin).