Weed Control in Pastures

— Written By and last updated by

Weed Control in Pastures

 What and Why?

As spring comes into full swing, pastures begin to grow. With new growth comes unwanted weeds. Weeds grow at a rapid pace than desired grasses, taking up the soil’s nutrients and shading the immature grasses from much-needed sunlight. The decrease in growth of desired grasses contributes to livestock not adequately growing and gaining, resulting in decreased profits.


Weeds thrive in areas where the soil is compacted or over. High traffic areas, holding pens, feeding, water, and shelter areas become the most densely populated with weeds. Once the weeds mature, they release seeds that spread to other parts of the pasture by wind, birds, or even on the hair or hooves of the livestock.

How and when to control?

The opportune time to control weeds is when the plants are in an immature stage of life when the weeds reach 4-6 inches in height for most species. At this stage, the weeds have leaf growth but are still vulnerable. I suggested that an herbicide be used that best fits the weed species, desired pasture species, and livestock operation. This stage typically occurs around mid to late April in this area. The proper timing does depend on the weather and temperature. If temperatures are lower, the timing may need to be late April or early May.

When timing is ideal, most herbicides are administered through a spraying technique. The herbicide is sprayed over all the species of grass and weed throughout the pasture. The herbicide then attacks the broadleaf species, killing the plant. It is essential to know what desired forage species are present in a pasture before choosing a herbicide. If the desired species is considered a broadleaf, the herbicide will attack this plant, too, eliminating it.


Killing weeds in a pasture will allow the desired species of grasses to grow and thrive, providing livestock with much-needed nutrition. This optimal nutrition will increase the growth and gains of an animal, increasing its quality of product and profitability.

For additional information on weed species identification, spraying techniques, and available herbicides, please contact Michelle South, Area Agent, Agriculture – Livestock, at N.C. Cooperative Extension – Avery County Center (828-733-8270) or by email at michelle_south@ncsu.edu.