Invasive Plant Species Control
Leafy Spurge
(Euphorbia esula)
Native Substitutes
- Virginia mountain mint (Pycnanthemum virginianum)
- Whorled milkweed (Asclepias verticillata)
- Grass-leaved goldenrod (Euthamia graminifolia)
- Round-headed bush clover (Lespedeza capitata)
Description
Appearance: Perennial forb, 2-3 1/2' tall; erect, branching, smooth stems growing from a deep vertical root. Stems, flowers, and leaves emit a white milky sap when broken that can burn skin.
Leaves: Alternate, small, oblong to lance-shaped, on the upper part of stem; scale-like on the lower part of the stem.
Flower: Small, borne by showy yellow-green bracts which open in late May; flowers bloom June into fall. Umbel-like cluster of 7-10 flowers at the top of each stem; single, stemmed flowers grow from leaf axils below.
Seed: Explosive dispersal from a seed capsule up to 15 feet; high germination rate; seeds remain viable in the soil for 7 years.
Roots: Extensive deep root system, vegetative reproduction from crown and root buds.
Ecological Threat
Rapidly invades primarily non-cropland disturbed environments. Is a threat mainly to mesic and dry prairies and savannas, quickly displacing native plants. Tolerant of a wide range of habitats, from dry to moist, and sunny to semishade. Most aggressive in dry soil conditions where there is less competition from native plants. Native to Europe and Asia it occurs across much of the northern U.S. in the grasslands and savannas of the Great Plains.
Legal Status: This plant is a prohibited noxious weed in Minnesota and must be controlled or eradicated as required by Minnesota Statutes, section 18.78.
Control Methods
| Mechanical | Chemical | Biological |
|---|---|---|
| Prescribed burning in conjunction with repeated treatment with glyphosate and 2,4-D | All require repeated application twice/year over several years to be effective; Picloram during true flowering, 2 weeks after yellow bracts appear, is 90% effective for small patches, but is very persistent in the environment and is the method of last resort. Do not use within root zones of trees and shrubs | Root-boring beetle, four root-mining beetles, shoot-tip gall midge |
Sources
Wisconsin Manual of Control Recommendations for Ecologically Invasive Plants, 1997
Minnesota Department of Natural Resources, Restore Your Shore CD, 2001
