Sunflower broomrape

Sunflower broomrape (Orobanche cumana) is a highly invasive, parasitic weed of the sunflower (Asteracea) family. It is unable to photosynthesize and relies entirely on the host plant. Sunflower broomrape causes significant declines in the health and productivity of plants in the sunflower family and could be devastating to sunflower production. The plants also produce hundreds of thousands of seeds,which remain viable in the soil for decades. 

Sunflower broomrape was discovered in Washington in 2025. WSDA took steps to eliminate the pest at the detection site and established a quarantine to prevent its spread. Even after public outreach about the pest, no additional sites have been detected. WSDA will continue to monitor the site and respond if further plants are found.  

• Sudden wilting or yellowing in sunflower plants
• Strange pale yellow to purple flowering stems near the base of sunflowers 
• Unexplained stunting or plant death 
• Prior to bloom, flower stalks somewhat resemble asparagus

• DO NOT DISTURB IT. This can unintentionally spread seed. 
• Take photos and report suspected sightings to WSDA immediately and await further instruction.
• Include your name, the location of the sighting, date of sighting, and photos with your report.

• pest@agr.wa.gov
• (800) 443-6684