June 15, 2007

Rangeland and pasture weeds are prominent this year in many grasslands.

Do you manage your grazing to allow adequate time for your grass to recover its vigor and competitiveness after grazing? If not, spraying weeds and brush just wastes money — they'll just keep on coming back. If grazing is managed well, weed control can pay good dividends.

Early June is the best time to control most perennials, annuals, and woody plants — remember that it's usually better to spray too early than too late. Please note that there are grazing restrictions following the use of some herbicides, so read and follow all label directions.

Small annual broadleaf weeds are controlled well by 2,4-D ester or Cimarron. Mixing some dicamba with these herbicides improves control of larger weeds. Be especially careful, though, using dicamba anywhere near sensitive crops, gardens, or trees because it can drift half a mile or more.

For tougher weeds, including most perennials like western ragweed, vervain, ironweed and broom snakeweed, Tordon is quite effective and provides some soil residual activity to limit new weed seedlings. Other good choices to control these tougher weeds are Grazon, which is a premix of Tordon and 2,4-D, Milestone, Redeem, and Overdrive.

When woody plants are your main problem, Tordon, Spike, Remedy, Surmount, and Pasturegard usually are your best choices in pasture and rangeland.Herbicides can be useful on grasslands when used properly, but only when your grazing management helps the effects to last.

Bruce Anderson
Extension Forage Specialist