Stem

Up to 10 ft. tall, green with purple spots, stout, hollow except at nodes and highly branched with lengthwise ridges

Leaves

Triangular, 4-12 in. long, finely pinnate-divided (fern-like) and lack hair (glabrous); leaflets have toothed edges; foliage has a musty odor

Flower

Small and white; arranged in umbrella-like clusters at end of a stalk

Root

Thick, deep taproot

Other

Grows best in moist sites; often infests crop fields, waterways, roadsides and waste areas; known to occur in Carson City, Douglas, Elko, Lander, Lincoln, Lyon, Nye, Storey, Washoe, and White Pine counties
Biennial; reproduces by seed
Highly toxic to animals and humans when consumed

Control

Repeated mowing or tillage prior to seed production is effective; hand-removal by cutting the taproot below the crown can also eliminate plants, avoid contact with skin
An insect biological control agent is available
Apply 2,4-D, chlorsulfuron, glyphosate, metsulfuron or triclopyr to actively growing young plants; aminopyralid, imazapic, or imazapyr preemergence or on young plants

Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Poison-hemlock, Extension, University of Nevada, Reno, Field Guide

Extension Associated Contacts

Heidi Kratsch

Also of Interest:


Nevada Noxious Weed Field Guide – Canada thistle Canada thistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Nevada Noxious Weed Field Guide – Malta starthistle Malta starthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Nevada Noxious Weed Field Guide – Perennial sowthistle Perennial sowthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Nevada Noxious Weed Field Guide – Purple Starthistle Purple starthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Nevada Noxious Weed Field Guide – Yellow starthistle Yellow starthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed. Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide

Associated Programs

Master Gardeners of Nevada

Program trains local gardeners to provide research-based horticulture information to Nevadans.

Garden plant and pest sprayers image by Olga Seifutdinova from Getty Images

Integrated Pest Management

Integrated Pest Management (IPM) is a strategy that reduces pests to tolerable levels with lower costs for the pest manager or home gardener and minimal effect on the environment. The IPM program at University of Nevada, Reno Extension focuses on identification and public education with resources for the community including classes, Spanish language resources and a pest directory.

Weed Warriors Invasive Weed Training

The Nevada Noxious Weed Education Program, Weed Warriors program tackles the growing problem of spreading noxious and nuisance weeds on public and private land.

Nevada Noxious Weed Field Guide – Poison-hemlock