May 21, 2010

Early to mid-June is a popular time to spray pasture weeds and woody plants, but it may not be the smart thing to do.

We often recommend using herbicides to control pasture weeds, but the more experience I get with grazing and pasture management, the less spraying I do. In fact, anytime a pasture is sprayed, it indicates that grazing has not been as effective as it could be or that the owner wants a quick fix.

First, for a pasture to be profitable, it must have high management input but controlled dollar input. Spraying costs money which might be saved with better management.

Second, livestock eat many plants we call weeds and when they do, these plants are no longer weeds. In fact, many weeds can be good feed if grazed while young and tender.

Third, unpalatable weeds usually become established in pastures after grass is weakened by severe grazing. They thrive when grazing management fails to encourage vigorous grass regrowth. And finally, unless pasture and livestock are managed to benefit both plants and animals, the weeds will be back despite your spraying.

If you graze properly but you wish to speed up the process of replacing uneaten weeds with vigorous grass, that's a good reason for applying a herbicide. Otherwise, spraying may be simply cosmetic and a waste of money.

Bruce Anderson
Extension Forage Specialist