Stem

Up to 6 ft. tall, semi-woody, waxy and lacks hair (glabrous); many stems can arise from each crown; often branched near top; branches arise from leaf axils

Leaves

Alternate, oval to lance-shaped, mostly 3-12 in. long, 1-3 in. wide, green to gray-green, lack hair and waxy; edges (margins) smooth to toothed and can also be curled; leaf bases DO NOT clasp stem; lower leaves larger than upper leaves

Flower

Small and white with 4 petals; arranged in dense clusters at the tips of stems
Seed pods are round, flattened, less than 0.1 in. diameter, usually covered with hairs; each seed pod has 2 chambers, each with 1 seed

Root

Creeping root system

Photo of perennial pepperweed bush with white flowers

Other

Grows best on moist sites; often found in floodplains, pastures, meadows, hay fields and along waterways; known to occur throughout Nevada
Perennial; reproduces by roots and seed
Also known as tall whitetop

Photo of a field of perennial pepperweed

Control

Mowing, digging, tillage, burning and grazing established stands is NOT effective
Apply chlorsulfuron, imazapic, imazapyr, or metsulfuron to actively growing plants through early-bloom; 2,4-D and glyphosate at bud to flower can be effective if repeated for several years

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

Extension Associated Contacts

Heidi Kratsch

Also of Interest:


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 – Iberian starthistle Iberian 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

Grow Your Own, Nevada!

Learn the secrets of high desert gardening

Green Industry Training

A workforce development program to train green industry professionals, who receive continuing education units for pesticide applicator, ISA-certified arborist and Qualified Water Efficient Landscaper

Nevada Noxious Weed Field Guide – Perennial pepperweed