Well maintained pastures are an excellent source of forage for many horses. In fact, pastures can provide 100% of a horse’s daily roughage requirement. They can also provide other health benefits, such as exercise. However, pastures need to be managed to maintain optimal productivity and prevent degradation.

Many factors in your area will determine which plants are adequate for your pastures, such as climate, soil, rainfall, and plant availability. This, in turn, will determine which months the pasture will be most productive for full time grazing. For example, a warm season forage, such as Bermudagrass, will begin to grow in the spring and reach full productivity in June and July. Growth usually begins to slow in late August or during the hottest summertime period when daily temperatures exceed 95° F. This is the general pattern for most other warm season grasses.

While not any single horse pasture is the same, there are universal tips that can help in maintaining pasture productivity. One of the first considerations with any horse pasture is stocking density. This means, how many animals can graze on any given acreage to maintain pasture productivity.  

  • The general rule of thumb is to provide at minimum 2 acres for an adult-sized horse.
  • 1 acre is roughly the size of an American football field.
  • For some regions of the country, or even during periods of drought, this should be increased.
  • Just how much you increase the acreage per horse will depend on your individual operation and region.

Another major management practice and tip is how to monitor your pastures to maintain optimum productivity. Again, this will depend on what type of plants are in your individual pasture and what region of the world you live in. However, here are some universal tips to help maintain productivity.

  • The height of the plants in a horse pasture should generally not exceed 8 to 9 inches. This ensures plants are not too mature and have adequate nutrients.
  • Pastures where plants exceed 9 inches should be mowed down to this height.
  • Plant height across most pastures should not be allowed to be grazed below 3 to 4 inches. This ensures plants can recover and prevents overgrazing.

Horses are selective grazers, and will usually seek out and graze young, succulent plants. This can lead to the death of the plant and thus harming pasture productivity. Therefore, to prevent overgrazing, rotational grazing is almost always recommended for horses.

  • Rotational grazing can be accomplished by dividing out smaller acreages using cross fences or electric tape to portion out select areas.
  • Once the designated acreage is grazed down to 3 to 4 inches, horses should be moved to the next area of the pasture. This is where the plants have been allowed to grow to an optimal 8 to 9 inches.
  •  If rotational grazing is not feasible, then it is recommended the pasture is mowed when possible to keep plant height uniform.

Finally, during the later summer months where pasture growth has slowed and plants are not reaching an 8- to 9-inch height, horses should be kept in a sacrificial area. This is an area that can serve as a dry lot and where horses can be fed hay while the pastures recover. It is a portion of your property that is “sacrificed,” meaning grass is not expected to grow.

  • A guide is to provide at minimum 400 square feet per adult horse in a sacrificial area.
  • Once the pasture has recovered, horses can be turned out to graze for limited time during the day. This would only be recommended if your pasture has recovered sufficiently.
  • Horses should be brought to the sacrificial area as needed.

To summarize, pastures are an excellent source of forage for many horses. In any pasture management system, and especially during the summer months, the following guidelines should be adhered to:

  • Stocking density at a minimum should be 1 adult horse per 2 acres of pasture.
  • Pasture plants should not exceed 8 to 9 inches in height, mow to this height if over 9 inches.
  • Horses should be allowed to graze on plants until most of the pasture is grazed to 3 to 4 inches in height.
  • Rotational grazing is the preferred grazing system for any horse operation.
  • A sacrificial area should be set aside to move horses as needed to allow pastures to recover; generally, this area will be needed for the later summer months as plant growth slows.
Chris J. Mortensen, Ph.D.