The following Agriculture & Natural Resources article printed in the 2020 Spring edition of the Oldham County Extension Newsletter.

Buttercup and Poison Hemlock – Two Troublesome Weeds

Buttercup and Poison Hemlock are two problem weeds that can be controlled now with herbicide sprays. An herbicide containing 2,4-D as the active ingredient is usually the most economical spray choice that will give good control.

Buttercup is a problem mostly in overgrazed pastures. There are several types of buttercup in Kentucky, plus mature leaves are often differently shaped than seedling leaves. Buttercup is toxic to livestock. Best control is achieved when sprayed before these plants begin blooming, which is tricky since these may go unnoticed until flowering. Scouting pastures by walking diagonally through each will give a good overview of what’s growing.

Poison hemlock is another toxic plant that can be found in pastures, hay fields, and on roadsides. It has a biennial life cycle, meaning each plant lives for two years. This weed spreads by producing many seeds. So care should be taken to control it in pastures, hay fields, and around barns. The poison hemlock shown here was growing around an old tree stump, adjacent to a hay field. Spraying patches like this now will help prevent future spread of this weed.

When it comes to toxic plants, it’s important to note that animals typically don’t choose to graze these unless good pasture isn’t available. Some animals, however, may graze these weeds simply out of curiosity.

The University of Kentucky Weeds page is a great resource on identifying and controlling weeds: weedscience.ca.uky.edu/forages

Written by Traci Missun, Oldham County Agriculture & Natural Resources Agent.