Leafy spurge is a creeping perennial that emerges each year from roots that may be exceptionally deep in soil. This weed does not survive under regular cultivation. It becomes serious when it invades pastures and rangeland. Mowing is not effective and is usually impractical. Sheep will graze leafy spurge enough to reduce competition with grass and to allow some production from the rangeland. Any control program, including herbicides, must be long term. Picloram or two or three applications of glyphosate seem to be a good starting point.
2,4-D
Rate 2 lb ae/A
Time Apply at bud stage and to regrowth 8 to 10 inches high.
Remarks Repeat applications are necessary.
Caution Avoid drift to sensitive crops.
Site of action Group 4: synthetic auxin
dicamba (Clarity)
Rate 0.5 lb ae/A
Time Apply when red sorrel has new foliage, usually November 15 to March 15. Spring application controls spring-germinating seedlings better than sprays applied earlier.
Remarks This treatment kills red sorrel seedlings and most of the old plants. It prevents surviving plants from setting seed.
Control is unknown, although DCPA (applied before snapdragon seed germinates) has been reported as effective.
