Typically when thinking about weed control in pastures and hayfields the main topic is controlling summer annuals. Most producers typically focus their control efforts on warm-season broad leaf weeds, such as pigweed, horse nettle, and dogfennel. However due to the mild winters we have been experiencing over the last several years many may need to broaden the
ir weed control efforts. Cool-season weeds, are persisting longer in warm-season pastures more frequently. So today I want to talk a little about a few problematic winter weed species and how to control them to make for a higher quality pasture or hay this spring.
Thistles are a persistent problem in pasture management. This invasive species is best fought during the winter or early spring in order to see effective control results. Herbicides are most effective on thistles in the rosette stage (lying flat on the ground). Once thistles begin to bolt and shoot a seedhead, they are much harder to control. 2, 4-D alone, 2,4-D + picloram, 2,4-D + dicamba, aminopyralid+ 2,4-D, or metsulfuron methyl are all potential chemical control options.
Henbit, swinecress, and chickweed are plants that are not generally considered major pasture weeds but now it can be a major competitor with bermuda and fescue in the early spring. Although 2,4-D alone may not eradicate henbit, it can easily be taken care of with other herbicides when sprayed early. Herbicides or mixtures of 2,4-D and dicamba, 2, 4-D + picloram, aminopyralid, and metsulfuron will do the trick. For best results, spray when these weeds are still small.
Broomsedge is another winter weed that stands out in pastures during this time due to its brown-orange color. It is important to understand that broomsedge cannot be controlled by herbicides during this stage of growth. It is also important to understand that if you are seeing broomsedge in your
pastures it typically means you are dealing with a soil fertility issue. You will want to take soil samples and with proper lime and fertilizer application the broomsedge will disappear over the next several growing seasons.
Pastures and hayfields simply need to be scouted to determine if control is necessary. However one way to get a leg up on your summer weed control is to apply aminopyralid (sold as Milestone or formulated with 2,4-D and sold as GrazonNext HL). If applied in February, aminopyralid will give some pre-emergent protection against those early germinating summer annual weeds.
Managing winter weeds from robbing space, sunlight, nutrients, and water from desired forage grasses is important to ensure quality a hay or grazing pasture this spring. Consider spending a little extra to control those weeds and it will pay dividends down the road.