By Webb Callicutt
Delta County Weed Program
Leafy spurge, Euphorbia esula, is located in eastern Delta County along lands irrigated by the Stewart, Minnesota and Turner Ditches. The Minnesota Creek Road area is the epicenter for leafy spurge.
This infestation has been there since at least 1990. It has spread westward via the Stewart Ditch as far as Crawford Road. Eradication is nearly impossible with leafy spurge once widespread establishment has occurred. The goal of the County is control and containment.
Leafy spurge is a perennial with extensive, deep, creeping rootstocks. Roots are dark brown with pink shoot buds. Leaves are linear and about 1-1/2 inches long. Flowers are inconspicuous and green. At the base of the true flowers, and emerging before them, are bright yellowish-green bracts that are often mistaken for the flowers. Seeds are in a pod, which when dry expels the seeds up to 15 feet.
The milky sap of leafy spurge can cause skin and eye irritation in humans and other animals. It can cause death of livestock. The toxicity remains even after the plants are dried. Caution must be taken when handling this weed.
Control efforts are to prevent seed production and stress the root system. Herbicides that are effective include Tordon and dicamba, both combined with 24D. Roundup (glyphosphate) is effective but is not selective. Biological controls have been effectively used in combination with mowing in one organic orchard in Paonia.