Foxtails are safe for horses to eat; however, they have low nutritional value and palatability and are, therefore, not ideal forage for horse pastures. | Photo: University of Kentucky's College of Agriculture

Despite the fact that horses graze year-round, no pasture forage species actively grows all year. Pasture grasses vary from season to season and even from month to month. Each new season brings limitations and availabilities to pastures, and understanding these rhythms will help horse owners take advantage of forages year-round.

The most important difference to understand is cool-season vs. warm-season grasses. Cool-season grasses, such as orchardgrass, bluegrass, and tall fescue, grow during the cool spring and fall months, while warm-season grasses, such as Bermudagrass and crabgrass, grow during the summer months.

Cool-season grasses are most productive when the air temperature is 65-75° Fahrenheit. They respond well to high soil moisture, cooler temperatures, and short photoperiods, making them most productive in the fall and spring. As summer arrives and temperatures increase, growth will slow and cool-season grasses will enter dormancy, sometimes referred to as the “summer slump