Latin Name: Lepidium draba
Origin: Asia and the Mediterranean
Physical Description: Perennial from the mustard family (Brassicaceae) this stout plant grows up to 2 feet in height. The flower is small and white with tiny heart shaped seed pods clustered around the flower head. The lower leaves and stem has tiny hairs that give it a soft and velvety feel while the upper leaves are typically hairless. The leaves are greyish green and clasp around the stem.
Habitat: It is found on a variety of loamy soils, from light to heavy, and prefers neutral to alkaline soils. It thrives in open, non-shaded habitats with moderate moisture, such as fields, meadows, pastures, open grasslands, roadsides, ditches, and gardens.
Impacts: It is allelopathic and can inhibit germination, growth and development of desirable plant species, including crops species. This allows it to outcompete with desirable plant species, impacting crop production and biodiversity. This plant contains toxins (glucosinolates) and can have impacts on livestock when ingested.
Reproduction: It reproduces by seeds, root stock, and creeping roots or rhizomes. It can spread vegetatively at a rate of 2 m/year. The flowering period is from May to July, with mature seed produced 1 month later. A single plant can produced between 1,200 to 4,800 seeds each year, with seeds remaining viable in the soil for up to 2 years.
Mechanical: hand pulling or digging is not recommended due to its extensive root and rhizome system. The roots can remain viable for up to a year and produce new plants, even when the top growth has been removed. Mowing or cutting seed heads can reduce the competitive ability of the weed and its ability to produce seeds if carried out prior to flowering, however this is ineffective against the established seed bank and creeping roots or rhizomes.
Chemical: The following active ingredients can control Hoary cress: 2, 4-D, Aminopyralid, Dicamba, Glyphosate, Imazapyr, and Metsulfuron. For available products, contact your local agri-supply store. Prior to any herbicide application, read and follow the label instructions.