Hoary alyssum can be an annual, biennial or perennial. The tap-rooted plant emerges in early spring. It is an erect or spreading plant, growing up to three feet tall, with multiple stems arising from the base of the plant. The thin stems branch near the top of the plant, and leaves and stems are covered in whitish, star-shaped hairs. The ó to 1ó inch, gray green leaves are alternate and lance-shaped; upper leaves clasp the stem. Hoary alyssum produces small white flowers, borne in clusters at the end of the stems, from May to September. There are four petals, however, since each petal is deeply lobed, the flowers can appear to have 8 petals. The small, oblong, flattened fruit has a short beak and is often covered with star-shaped hairs.
Hoary alyssum can be controlled through mechanical and chemical means. Hand-pulling is effective on small infestations; plants should be pulled before they can go to seed. Contact the weed control board for site-specific chemical recommendations.
Information taken in part from: MSUE/Project GREEEN “Identification, Livestock Toxicity and Control of Hoary Alyssum in Christmas Tree Plantations and Forages”