Management tips to control weeds in grass pastures and hayfields

Following good pasture management practices is one of the best ways to eliminate weeds and unwanted plants in grass pastures and hayfields. Weedy type plants reduce quality, and sometimes quantity, of desirable forages available to livestock. Some plants are even potentially poisonous to grazing animals.

To reap the most forage quantity and quality from pastures, use management practices to encourage growth of a vigorous, dense stand of desirable forage grasses, yet limit germination and growth of unwanted plants. Remember, weed seed can germinate in thin pasture stands, and unwanted plants are more prone to become established in these areas.

Recognize that all weeds aren’t detrimental as livestock forage. Some weedy plants have nutritional value, especially those used in the early vegetative growth stages such as chicory and crabgrass.

Good pasture management starts with timely mowing and good grazing practices. Well-timed mowing before weedy plants can produce new seed helps prevent production and spread of weed seeds. Where perennial weeds dominate, frequent mowing can curtail weeds’ growth by depleting their root reserves. If you use rotational grazing, be sure to avoid over-grazing that reduces the competitive capabilities of desirable forage species.

Maintaining the optimum soil acidity/alkalinity and fertility levels is another weed prevention practice. Take routine soil tests to ensure the best levels for pasture growth and quality. Also, keep fence rows and adjacent fields free of troublesome weeds such as musk thistle and multiflora rose.

In some cases, herbicide use probably is the most desirable weed-control method. However, it’s important to remember that you can’t effectively control all weeds with a herbicide product. Sometimes herbicide use is cost-prohibitive. So, when considering herbicide use, determine the types of weeds to be controlled, their life cycles and the best time of year to apply the herbicide. Remember to note any grazing or forage harvest restrictions.

Avoid applying herbicides in mid-summer, because many common products for pastures can injure nearby, sensitive broadleaf crops like tobacco, vegetables and ornamentals, especially under unusually high air temperatures and humidity.

There are two generally preferred times of year to apply herbicides in grass pastures: in the fall to early winter months, or in the spring after plants begin actively growing.

As is true with any good management program, use a variety of practices to prevent and combat weed infestations in pastures. Remember, timely mowing is an effective cultural weed control practice. Whereas, apply herbicides only if and when the situation warrants their use.

Contact your Boyle County Cooperative Extension Service for more information on managing weed problems in pastures.

Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expression, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability. University of Kentucky, Kentucky State University, U.S. Department of Agriculture, and Kentucky Counties, Cooperating.

Jerry Little, County Extension Agent for Agriculture/Natural Resources