It’s a sign of spring in the Mid-South, masses of pretty, but troublesome yellow flowers sprouting up across pastures. The aggressive and potentially toxic hairy buttercup is a concern for many cattle producers, and it’s best managed with a fall herbicide application, according to Neil Rhodes, Extension weed specialist with the University of Tennessee.
“Historically, we talked about managing this weed in the winter or spring,” said Rhodes. “Now, we’re preaching a fall application. If we have a mild fall, we can do a good job on hairy buttercup from mid-October all the way up to Christmas and New Year with 2,4-D.”
Rhodes, speaking about pasture weed management at the Milan No-Till Field Day, said his own research, along with producer experiences, showed fall to be a better time to spray buttercup for several reasons. First, these weeds are small and actively growing in the fall.
“One of the most important keys to getting good results is to spray buttercups before they bloom. This is an automatic with fall applications.”
Rhodes said fall weather conditions are typically preferable for spray applications than winter and spring, when it’s wet and windy. Fewer vegetable gardens and active greenhouses are in the crosshairs of off-target herbicide drift in the fall, too.
“We don’t really have to have warm weather,” said Rhodes. “Buttercup is actively growing if you have three days in a row of at least 60-degree temperatures. That will stimulate growth and promote uptake by the herbicide.”
What to spray
“We’re recommending in most situations 2,4-D ester, which is the cool-season herbicide formulation, at the rate of 2 pints per acre,” said Rhodes. “That’s also a good treatment for musk thistle.”
“Grazon and DuraCor are very good herbicides, too, but one good thing about using 2,4-D in the fall and not one of our residual herbicides, is it allows you to come back in February and drill in clover.”
Since buttercup is a sign of overgrazing and poor forage stands, producers may be looking to renovate pastures. Rhodes advises taking care of weed issues first.
“Let’s get the weeds cleaned up first, grow some good grass, and then enhance that grass with clover.
“Another question I get all the time is, ‘How many years do I have to spray?’ The good college boy answer is it depends. If your pastures have grown up year after year in buttercup, there’s a large seed reserve there.”
Rhodes also discussed management options for tall ironweed and best methods for cleaning up fencerows. You can view his entire presentation as part of the Beef Tour at milannotill.tennessee.edu.