Brassicaceae or Mustard Family
Growth habit: Biennial, grows 1 to 3 1/2 feet tall.
Leaves: Greyish-green with star-shaped hairs. Basal leaves 1 to 2 inches long with slender stalks. Stem leaves face upward, pressed to stem. Lower leaves with short stalks, upper leaves lack stalks.
Stems: Erect, branched and covered with star-shaped hairs.
Flowers: White, deeply notched petals on slendar stalks. Sepals hairy and drop off.
Seeds: Flattened oval seed pods with star-shaped hairs close to stem. Pod chambers contain 3 to 7 seeds.
Reproduction: By seed.
Habitat: Fields, pastures, roadsides.
Handpulling: This is an effective method of control when used on small infestations and scattered individuals that are just establishing or missed by herbicide treatments. Effective handpulling requires the removal of the taproot, which is most easily accomplished when soil is moist. Repeated treatments are required to deplete the seed bank, and all plants that are past bud stage should be removed in plastic bags to prevent seed spread.
Mowing: Mowing alone is not a recommended method of control for this species due to the damage to competitive, desirable vegetation.
Biological Control: N/A
Grazing: To date, grazing has not been used as a method of control for hoary allysum and is not recommended.
Herbicides: Due to hoary allysum's tendency to germinate throughout the growing season, repeated treatments are needed to deplete the seed bank in established infestations. The following herbicides are labelled for control of hoary allysum. Always consult product labels and read them carefully to ensure correct species/land management usage and chemical application.
|Trade Name:||Active Ingredients:||Rate:||Efficacy:||Comments:|
|Escort||metsulfuron||1 oz/acre||most effective if used when plant is in rosette to bud stage with a non-ionic surfactant||Cannot be used near wells, surface water or shallow ground water|
|Telar||chlorsulfuron||1 oz/acre||most effective if used when plant is in rosette to bud stage with a non-ionic surfactant|
|Chaparral||metsulfuron + aminopyralid||2-2.5 oz/acre||most effective in spring or fall when applied to seedlings and rosettes||Cannot be used near wells, surface water or shallow ground water;
cannot be used in landscaped areas and current or future gardens, mulch or manure from treated area should not be applied to gardens or composted vegetable gardens.