Weed Control

Other names: Nodding Thistle

Life Cycle: Biennial or winter annual; only reproduces by seed.

By Dr. J.D. Green, Extension Weed Scientist - Using good pasture management practices can help minimize weeds and unwanted plants in grass pastures and hayfields. To get the most quantity and quality from pastures, use management practices that encourage growth of a vigorous, dense stand of forage grasses and limit germination and growth of unwanted plants. Weeds that reproduce by seed readily germinate in thin pasture stands, and unwanted plants are more prone to become established in these areas.

This past year the Master Grazer Educational program conducted several demonstrations across KY for producers to see best management practices related to pasture management. One of these demonstrations was implemented in Lewis County by cow/calf producer Mike Setters. Previously, he has completed the Master Grazer and Master Cattleman programs and uses many of the practices taught in these programs, such as rotational grazing and improved access to water.

Dr. J.D. Green, Extension Weed Scientist - One of the signs that spring has arrived is when the yellow flowers of buttercup begin to appear, but it’s during the winter months that the vegetative growth of buttercup takes place. As a cool season weed, this plant often flourishes in over grazed pasture fields with poor stands of desirable forages. In fact, many fields that have dense buttercup populations are fields heavily grazed by animals during the fall through the early spring months. 

By J. D. Green, Extension Weed Scientist

Tall ironweed (Vernonia altissma Nutt.) is one of the more commonly found weeds in grazed pasture fields and other non-cropland areas (Figure 1). In Kentucky, tall ironweed is ranked as the most troublesome and third-most common weed found in grazed pastures. The quantity of grass available for grazing can be substantially reduced in pastures by the presence of tall ironweed because of its unpalatability to livestock. This further leads to an increase in tall ironweed populations over time as animals graze and selectively avoid this weed.