Absinth Wormwood
Artemisia absinthium
Washington State Classification
Class C — Widespread, County-Selected Control
Absinth wormwood will outcompete desirable forbs and grasses in pastures, fields and native grasslands.
Quick Reference
Identification
Growth Habit
Absinth wormwood is an herbaceous perennial with a strong sage odor. It commonly grows to 3 feet tall (sometimes to 5 feet tall). Plant is covered with fine, silky hairs and has a gray-green appearance.
Leaves
Leaves are 2 to 5 inches long, divided two or three times into deeply lobed leaflets. Leaves reducing in size going up the stem.
Flowers
Flower stalks appear at each upper leaf node and produce numerous yellow flower heads that are 1/8 inch in diameter.
Fruit & Seeds
Seeds (achenes) are smooth and hairless.
Impact
Absinth wormwood will outcompete desirable forbs and grasses in pastures, fields and native grasslands. It easily establishes in disturbed areas where there is little plant competition.
Ecology & Spread
Habitat
The plant grows in both dry and moist soils. Absinth wormwood is generally found on dry soils in pastures, cropland, farmsteads, shelterbelts, roadsides, fence rows and waste areas. Please click here to see a county level distribution map of absinth wormwood in Washington.
Spread Mechanisms
Reproduction
Reproduces primarily through seed production, but can also spread by short roots. The plant is a prolific seed producer with seedlings emerging anytime from late spring to early fall. Seeds may remain viable for 3 to 4 years.
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Control Methods
Mechanical
- Tillage can prevent establishment of absinth wormwood in crop production areas. Mowing may prevent seed production if mowed several times throughout the growing season, but mowing may be difficult in fence rows or rocky areas. Burning may not be an effective control method for absinth wormwood as infestations are not reduced and may increase.