Stem

0.5-2 ft. tall; branched near top; covered with short hairs

Leaves

Alternate, 1-4 in. long, blue-green, oblong to lance-shaped and covered with short hairs; edges (margins) are toothed to smooth
Lower leaves have short leaf stems (petioles); bases of upper leaves have lobes that clasp the stem

Flower

White with 4 petals; occur in clusters that give plant a flat-topped appearance; occur from spring to early-summer
Seed pods are oval to heart-shaped; each contain 2 seeds

Root

Deep, spreading root system

Photo of hoary cress infestation next to a lake

Other

Grows best in disturbed, alkaline soils; often found in pastures, fields, roadsides, rangelands, waste areas and along waterways; known to occur throughout Nevada
Perennial; reproduces through roots and seeds
Also known as whitetop; 3 species occur in Nevada: hoary cress (C. draba) is most common but lens-podded whitetop (C. chalapensis) and hairy whitetop (C. pubescens) also occur

Control

Dig or pull individual plants for small infestations; remaining roots can produce new plants; frequent tillage or mowing for several years can reduce plant density
Apply 2,4-D to actively growing plants prior to bud stage; chlorsulfuron or metsulfuron from bud to early bloom; imazapic from full bloom until necrosis

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

Extension Associated Contacts

Heidi Kratsch

Also of Interest:


Paradise Valley Weed Control Demonstration Plots: Hoary Cress Noxious weeds are species considered detrimental or destructive, and difficult to control or eradicate. In Nevada, noxious weeds are prohibited in commerce, and state law mandates their control or management. Schultz, B. 2005, University of Nevada Cooperative Extension
Nevada’s Priority Agricultural Weeds: Hoary Cress Plants commonly referred to as hoary cress (Cardaria sp.), or short whitetop, are one of three different but closely related perennial forbs. The Cardaria species are widespread across all eleven Western states, including every county in Nevada. B. Schultz, S. Foster 2021, Extension, University of Nevada, Reno, SP-21-03

Associated Programs

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

Integrated Pest Management

Integrated Pest Management 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 the University of Nevada, Reno focuses on identification and public education with resources for the community including classes, Spanish language web pages and a UNR pest directory.

Master Gardeners of Nevada

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

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 – Hoary cress