Hoary cress, also called short whitetop, is a deep-rooted, invasive mustard perennial that poses a threat to both crop and rangelands in the Western United Sates. Accidentally introduced to North America from Western Asia and Eastern Europe as a seed contaminant, hoary cress currently infests more than a quarter million acres of public and private land and is found on the noxious weed list of 14 states and one Canadian province.

Hoary cress spreads both by seed and creeping roots and can live in a wide variety of environmental conditions. It is a perennial that grows up to two feet tall, but is often shorter on very dry sites. Leaves are grayish-green, up to 4 inches long and are shaped like arrowheads. Flowers are white with 4 petals, ¼ inch across and bloom in April and May. These dense umbrella-like flower clusters give the weed a flat-topped appearance early in the season, but this is lost as the stem elongates. Two small, flat, reddish-brown seeds are contained in each of the heart-shaped seed pots.

Hoary cress is easily spread by cultivation and is difficult to eradicate due to an extensive and deep root system. Some herbicides are registered for hoary cress. Eradication is most successful when attempted before the plant blooms or while it is still in bloom.

Now is the time of the year to begin your battle against Hoary cress. For more control information contact the Churchill County Mosquito and Weed Abatement District at 423-2828.