Widely spread across Utah. Control efforts focus on reducing or eliminating new or expanding populations.
Quick Facts
Report your sighting through EDDMapS to help us track and respond to new infestations.
Report on EDDMapSPoison Hemlock
Conium maculatum
Overview
Poison hemlock is one of the most toxic plants in North America. All parts are highly poisonous to humans and livestock. It is a biennial plant that invades roadsides, riparian areas, and disturbed habitats. It is the plant used to execute Socrates in ancient Greece.
How to Identify
Biennial 3-8 feet tall. Hollow, purple-spotted stems (key identification feature). Finely divided, fern-like leaves. Small white flowers in umbrella-shaped clusters. Musty, unpleasant odor when crushed.
Control Methods
Wear gloves and avoid skin contact - all parts are toxic. Hand-pull or dig before seed set. Herbicide treatment for larger infestations.
Herbicide Recommendations
2,4-D, dicamba, or glyphosate. Apply in early spring on rosettes. Dispose of plant material carefully - do not burn.
⚠️ Always read and follow pesticide label directions. Contact your county weed superintendent for site-specific recommendations. Permits may be required near water.
Need help managing this weed?
Skyline CWMA can connect you with technical assistance, cost-share programs, and licensed contractors for treatment on your property.
