Leafy Spurge Management
Overview
Leafy spurge, Euphorbia esula, is a widespread noxious weed throughout the USA and southern Canada. This weed has special capability to rapidly multiply and overtake desirable vegetation. Since cattle do not consume leafy spurge and avoid areas infested with this weed, the vast spread of leafy spurge will cause economic losses for livestock business. In Minnesota, by law, it is mandatory to control noxious weeds, such as leafy spurge.
Identification
Leafy spurge has a flat-topped cluster of yellowish-green and numerous narrow, smooth leaves along the stem. The plant has bluish-green leaves and stems, which turn orange in fall before dieback in winter. Typically, the plant grows up to two feet tall or more surrounded by several non-flowering plants spotted around the flowering leafy spurge. One of the identifying features of leafy spurge is that stems, leaves and flowers emit a white milky sap when broken.
Biology
Leafy spurge is perennial, meaning it lives for more than two years. Early in the spring, leafy spurge begins growing from buds on the crown (the connection between root and stem) and roots. Later, leafy spurge continues to grow from seeds throughout the growing season. Depending on the geographic location and weather conditions, yellow-green bracts develop on stems in May or early June followed by green flowers about two weeks later. Flowering is usually completed by mid-July. Seeds usually develop for 20 to 30 days after flowering. Leafy spurge becomes dormant in dry and hot areas in late summer, but growth can resume in the fall before winter dormancy occurs.
Habit
- Leafy spurge grows in a variety of dry and moist habitats, such as flood plains, riverbanks, grasslands, ridges and mountain slopes.
- This noxious weed can dominate cropland, pastures, rangeland, roadsides and waste areas. It is found less frequently on top slope and shoulder slopes.
- Leafy spurge is an aggressive weed that can compete and take over desirable plans, especially in disturbed or dry situations.
Management
Once established, leafy spurge is persistent and can be hard to control without a combination of culture and chemical control efforts over an expanded period of time.
Cultural Methods
Maintaining a healthy vigorous grass growth by proper irrigation or the use of a balanced fertilizer makes grass more competitive with leafy spurge. Sheep and goats grazing, handpicking, grass seeding as well as mowing and burning methods provide short-term solution for reducing leafy spurge infestations because of the recovery capability of this plant.
Chemical Method
A proper timing of herbicide applications is essential for success. Treatments with EPA approved herbicides are most effective when applied in spring at flowering growth stage. To manage any leafy spurge re-growth, fall application of herbicide is also recommend. However, in some situations, chemical management methods can be effective against leafy spurge only when applied at the right time for three to four consecutive years.
