Identification and Reproduction

Identification: 

• Orange hawkweed is an invasive flowering perennial in the Asteraceae (daisy) family.
• Single erect stem can grow upto one metre tall and is covered in hairs but leafless. 

• It has very hairy leaves that form in a central basal rosette. 
• Flowers are orange and dandelion-like. 

Reproduction: 

• Spreads by seeds that are easily dispersed by wind
• Vegetatively grow through stolons (above ground) and rhizomes (below ground). 

Habitat & Ecology

• Orange hawkweed prefers well-drained, coarse-textured soils.
• It will invade open and disturbed areas like pastures and roadsides as well as wetlands.
• Similar to yellow hawkweed, it is known to hybridize with native species. 

Impacts

Social: 

• Displaces crop yields in agriculture. 
• Reduces forage availablilty for livestock 
• Since orange hawkweed can establish quickly on deforested sites it can impact reforestation measures. 

Ecological: 

• It outcompetes other native plants, reducing forage and biodiversity. 
• Forms monocultures. 
• Has allelopathic properties that prevents growth of other plants.

Management

Mechanical/Manual Control: 

• Prior to flowering digging may be effective. Ensure that entire roots are removed. 
• Small infestations can be hand pulled. Be sure to collect all stolon and root fragments to prevent regrowth. 

Biological Control: 

Currently a stolon-feeding wasp and a root-feeding hover fly are being researced in BC. 

Chemical Control: 

• Picloram, aminopyralid, 2,4-D are effective on orange hawkweed. 
• Another consideration is to fertilize surrounding native vegetation in the spring. This will help facilitate growth to help outcompete with the invader. 
• Please carefully read and follow herbicide labels prior to application. 

For alternative planting options to orange hawkweed download the ISCBC's Grow Me Instead brochure (pg. 39 and 40).

Resources

Download A Guide to Weeds in British Columbia for Orange Hawkweed here.

For further details on Orange Hawkweed control please refer to the Metro Vancouver Best Management Practices for Orange Hawkweed(pg. 12-20)

Header photo (Sapin88).