In Montana, hoary cress is predominantly found in pastures and rangeland, but has the potential to spread to adjacent cropland. These weeds are generally found in disturbed areas dominated by other exotic species, such as smooth bromegrass and Russian knapweed . The three species are members of the mustard family, which can be easily identified because they all have a flower consisting of four petals and six stamens. The plants grow from 10 to 24 inches tall. A single plant produces from 1,200 to 4,800 seeds each year.
Small infestations spread by rhizomes which are underground stems capable of producing shoots.
A single plant can spread to an area 12 feet in diameter in its first year of growth. The most cost-effective method for managing these weeds is to prevent their encroachment. Limit seed dispersal by refraining from driving vehicles and machinery through infested areas during the seeding period, and wash the undercarriage of vehicles and machinery before leaving infested areas. Campers, hikers, off-road vehicle enthusiasts and horseback riders should brush and clean their equipment and animals, and place discards into a hot fire before leaving an area. Weed-seed free forage should be used.