What do these weeds have in common?

By Greg LaBarge, CCA, Ohio State University Extension

What do marestail, cressleaf groundsel, purple deadnettle, wild carrot, birdsrape mustard, poison hemlock, dandelion, annual bluegrass, and Canada thistle have in common? These winter annual, biennial and perennial weeds are effectively controlled with fall herbicide applications. So before you pack the sprayer away in the barn, check for these weeds in your just harvested corn or soybean, emerging wheat, and pasture or hay fields.

Commonly asked questions about fall herbicides are how late in the fall can herbicides be applied? At what point is it too cold to apply? Dr. Loux has applied well into December under some very cold conditions and still obtained effective control of winter annuals. He suggests applying before Thanksgiving and aiming for a stretch of warmer weather if possible, but the effective treatments should work regardless. After extended periods of freezing weather, perennials such as dandelion, thistle, and dock shut down, resulting in reduced control.… Continue reading