Hoary Cress

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Cardaria draba

Photograph by Gerald D. Carr

Hoary cress, also known as whitetop, is an invasive, non-native, creeping perennial that grows up to two feet tall. It produces low quality forage and the dense infestations outcompete desirable plants. Infestations of Hoary cress are common around Taos.

The foliage contains glucosinolates, which are toxic to cattle. They decompose into allelopathic compounds that can impede germination and growth of native and other desirable plants.

Hoary cress has oblong to lance-shaped leaves, stems are slightly hairy, and leaves are attached directly to the stem and are bluish-green in color. It produces small, white flowers that grow in dense clusters.

Management recommendations include hand-pulling prior to seed maturation (will help slow the expansion of infestations) but since Hoary cress reproduces primarily from root systems, effective management strategies will address both aboveground and underground plant structures.                

Photograph by Gerald D. Carr
Photograph by Craig Althen
Photograph by Craig Althen
Photograph by Gerald D. Carr

View an educational video featuring New Mexico State University’s Extension Weed Specialist Dr. Leslie Beck!  This video is specific to Hoary cress and Perennial pepperweed in Taos County and was the result of a collaboration between Taos Soil & Water Conservation District and New Mexico State University.