As cooler temperatures pump the brakes on plant growth in perennial pastures, grazing management must shift to accommodate the change of pace. This slowdown is especially prevalent in cool-season grasses and can affect grazing livestock, including horses.

In a recent article from the University of Minnesota, Krishona Martinson and Hannah Lochner prompt horse owners to walk through pastures and observe forage conditions. To prolong the grazing season and promote stand persistence, they encourage readers to avoid overgrazing grass, rejuvenate thin forage, control perennial weeds, and adjust soil fertility this fall.

Don’t overgraze. The authors note horses do not graze pastures uniformly because animals tend to prefer shorter, younger plants to more mature forage. Not only does this material typically fail to provide sufficient nutrients for horses to maintain body weight, but grazing grasses too short can be detrimental to forage regrowth.

“Grasses store nonstructural carbohydrates, starches and sugar, for energy in the lower 3 inches of the plant,” the authors explain. “Grazing or mowing below 3 or 4 inches can stunt plant growth or lead to barren areas that are prone to weed growth.”

What’s more is that the higher starch and sugar concentrations found in lower plant parts can be problematic for horses that are prone to laminitis. Therefore, it is imperative to move horses to a different paddock before overgrazing occurs.

“If removing horses from the pasture is not an option, make sure to provide their total daily ration in hay or an alternative feedstuff as if they were not on pasture,” the authors suggest. “This will allow horses to meet their daily needs but also help prevent them from venturing to eat weeds or toxic plants.”

Overseed or reseed. Late summer can be an opportune time to establish forage when there is adequate moisture, cool weather conditions, and less weed pressure. Although the window of opportunity to overseed or reseed grass forages may be coming to a close in Northern states, there is still time to enhance a thin stand.

“Common grass pasture species include timothy, orchardgrass, and smooth bromegrass,” the authors state. “You can plant turf-type lawn grasses like Kentucky bluegrass in higher traffic areas or to serve as a good base for your pasture.”

If overseeding, plant forage at 12 to 15 pounds of seed per acre. For reseedings, use a no-till drill or administer light tillage ahead of broadcast seeding new forage. With that said, even though light tillage will improve seedling establishment, it may intensify weed emergence.

Control perennial weeds. Fall herbicide applications are a useful tool to control perennial weeds in pastures. This is the time of year when plants are beginning to translocate carbohydrates to their roots for winter survival, which provides a direct route for herbicides to enter plant roots and kill weeds at the source.

“Always read the entire label and follow the manufacturer’s instructions and grazing restrictions. Make sure to select a product labeled for pastures,” the authors assert.

Take soil samples. In addition to herbicide applications, determine what fertilizer applications may be necessary to improve pasture conditions for next year. The authors suggest taking soil samples now when soil is relatively stable since plants have taken up most of the soil nutrients they will consume for the season. It also goes without saying to take soil samples before the ground freezes later this fall.