Get to Grips with Grassland Weed Control

Grassland is the largest and most important crop in Northern Ireland, providing the most cost-effective source of feed for cattle and sheep. However, the productivity and quality of grasslands are under constant threat from weeds. Effective weed control is not just a matter of aesthetics—it is essential for maximising yields, protecting livestock health and ensuring the long-term sustainability of grassland farming.

Weeds such as docks, thistles, ragwort and rushes compete directly with productive grasses for light, nutrients and water. This competition leads to a reduction in both the quantity and quality of forage available for livestock. Research highlights that a 10% weed infestation typically results in a 10% loss in grass yield. In practical terms, a 10-acre field with 10% weed cover is effectively producing only 9 acres’ worth of grass, significantly reducing the area available for grazing or silage production.

By controlling weeds, farmers can maximise grass yields and improve the nutritional value of forage. This supports higher stocking rates and better animal performance, as more palatable and digestible grass is available for grazing. Weeds such as docks and chickweed can hinder silage fermentation, resulting in poor-quality feed that livestock may reject or that may spoil quickly. Effective weed management ensures cleaner, higher-quality silage.

Weeds like ragwort, are toxic to livestock and can cause illness or even death if ingested. Thistles can also spread diseases like Orf among sheep. Controlling these weeds reduces the risk of poisoning and disease transmission, safeguarding animal welfare.

Dense, well-managed swards suppress weed establishment and prolong the productive life of grassland. This reduces the need for frequent reseeding and minimises input costs over time. Now is an ideal time to control weeds in grassland before they get too mature and are more difficult to kill. If weeds are controlled now before they set seed, the further spread of these weeds are prevented.

When selecting herbicides the first thing to do is check the range of weeds in the fields and identify if clover is part of the sward. At Fane Valley, we stock a wide range of grassland herbicides that provide control of both common weeds such as docks, chickweed, and nettles as well as the less common weeds. We also have a range of bio stimulants, which can be co-applied with herbicides to reduce checking of grass while also providing a timely boost to growth rates.

For more information on grassland weed control please contact your local Fane Valley Agronomist or call 028 9261 0485