Spring Control of Winter Weeds in Hay And Pasture

Now is the time to scout hay and pasture fields for the presence of winter annual and biennial weeds, especially those that are poisonous to livestock such as cressleaf groundsel.  These weeds are resuming growth that started last fall and they are most effectively controlled with herbicides while still small.  In addition to cressleaf groundsel, weeds of concern that should be treated soon include the following:  poison hemlock, birdsrape mustard (aka wild turnip), wild carrot.  Herbicides are most effective on these weeds in the fall, but they can be controlled in spring, preferably when still in the rosette stage.  Control becomes more difficult once stem elongation (bolting) starts.