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

Stem

  • 0.5-2 ft. tall; branched near top; covered with short hairs
Photo of hoary cress stem
 

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 
Photo of hoary cress plant with green leaves

 

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
Photo of hoary cress plant with white flowers on top
 

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

Learn more about the author(s)

Heidi Kratsch
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