Orange hawkweed

Originally from Europe, orange hawkweed was exported widely as an ornamental but has escaped cultivation. It prefers well-drained and course textured soils with low organic matter. While orange hawkweed can tolerate shade, it thrives in wide open areas. Infestations commonly occur in fields, meadows, forest clearings, pastures, farmland and other disturbed or modified habitats. Orange hawkweed can also thrive in residential backyards and readily invades lawns. 

• Orange hawkweed outcompetes native species and desirable forage species. 
• It reduces biodiversity.  
• Ranching and agriculture are impacted by decreasing yields and quality of forage production resulting in low stocking rates. 
• Orange hawkweed may have the most impact on the forest industry, as it often spreads along roads or areas that are not reforested, and has a high risk of establishment.  

The most effective way to ensure that your lands do not become infested with orange hawkweed is by prevention. Here are some recommendations to prevent invasion: 

• Maintain your crops and natural lands in a healthy, vigorous condition to ensure a competitive plant community. 
• Regularly patrol your property for orange hawkweed plants and immediately control or remove infestations before seed set.  
• Cooperate with adjacent landowners and encourage them to prevent orange hawkweed spread. 
• Immediately re-vegetate disturbed, bare soils with a suitable seed mixture that provides dense, early colonization to prevent weed invasion.  
• Do not move contaminated soils to a new area.  
• Plant suitable alternatives in your garden such as scarlet gilia, golden-aster, columbine and brown-eyed Susan.  
• Do not purchase wildflower mixes that contain invasive hawkweed species.

• Hand-pulling or digging can be done for small infestations, but ensure that all roots fragments are removed.  
• Cultivation or tilling is not recommended as root fragments can generate new plants.  
• Tarp and bag removed plants, plant parts, and seeds and dispose of at a landfill. Cut plant parts should undergo deep burial (at least 5 m deep) at a landfill.  
• Burning and composting is not recommended.  
• Chemical control is also an option. Before applying herbicides, read the label for full use and precautionary instructions.  
• For further information on the selection and application of chemicals to protect your crop, contact AgriService BC at 1-888-221-7141 or email AgriServiceBC@gov.bc.ca.  
• A root feeding hover fly (Cheilosia urbana) was released in 2017 as a biocontrol agent for orange hawkweed in BC. Another stolon-tip fall wasp (Aulacidea subterminalis) was released in 2011. More research is underway for the effectiveness of these species.