Managing Warm-Season Grass Pastures

Native legumes can increase grass production and pack a positive nutritional punch for grazing livestock. Seeds of native legumes, such as Illinois bundleflower and roundhead lespedeza, among others, can be sown with a native warm-season grass mix to improve the value of the planting for livestock and wildlife.

Add legume seeds to the grass seed mix at planting.

If restoring prairie or creating wildlife habitat is among your goals, use only native Missouri legumes and wildflowers.

If livestock forage is your sole objective, you may opt for less expensive introduced legumes such as Korean or Kobe lespedezas, or alfalfa — these should be established a year after the grasses are seeded. These legumes will boost hay production and help maintain crude protein of the forage above eight percent.

Do not plant:

• Domestic legumes, such as birdsfoot trefoil, that can be highly competitive. 
• Sericea lespedeza, sometimes advertised as a forage legume. It is an extremely invasive exotic plant that should never be planted.

The primary benefits of using native grass for hay are ease of maintenance, dependable production, and harvest during a normal lull in farming operations.

A stand of native grasses seeded with a legume will produce a consistent 2 to 3 tons of hay per acre when harvested in July. Since the hay is harvested after crops have been planted and cool-season grasses have slowed growth, native haylands help to reduce the spring rush of field work.

The quantity and quality of warm-season grass hay depends upon the harvest date.

Ideal haying dates in Missouri

• Switchgrass: June 15–July 1
• Big bluestem: July 1–15
• Indian grass: July 15–30

Do not mow after Aug. 1.

Leave a 4- to 6-inch stubble when mowing. Regrowth after mowing may be grazed after a killing frost but some protective cover should remain throughout the winter.

To sustain high forage yields and desired grass composition, burn native grass plantings periodically.

• Conduct burns when new growth on bluestems is one inch high. This condition varies by weather conditions and region of the state, but usually occurs in early April in south Missouri and early May in north Missouri.
• Burn hayland every three to five years.
• Burn pastures with only one grass species every third year.

When two or more warm-season grass pasture units are available, burn the first unit to be grazed that year.

Adequate safety features for controlled burning can be designed into warm-season grass plantings.

• Plant warm-season grass adjacent to cool-season grasses, cropfields or other areas that will act as a natural firebreak during prescribed burning.
• Construct fire lanes in warm-season grass pastures by mowing an 8- to 16-foot-wide strip the year prior to burning before the cattle are removed from the pasture. The cattle will graze the tender new growth on this strip and leave less fuel to deal with the following spring.

Adding a warm-season grass pasture to a cool-season pasture system will improve the efficiency of the forage program. Warm and cool-season grasses are most nutritious while they are vigorously growing. Cool-season grasses such as brome and fescue grow most during the spring and fall. Warm-season grasses (bluestems, Indian grass, switchgrass) grow most in the late spring and summer.

By fully utilizing each species of grass during its prime quality, you can keep your herd feeding on high-nutrition forage the entire grazing season. This is called a complimentary, or rotational, forage system. In general, the amount of warm-season pasture should be one-third to one-fourth the total pasture acreage. 

These tables show the best dates for grazing warm- and cool-season grasses.

Guidelines For Rotation Grazing Cool-Season And Warm-Season Grass Pastures

* 1. Intensive grazing season (double-stocking rate) 2. Standard grazing season

 **Pure stands of warm season grass: 3. switchgrass 4. big bluestem 5. Indiangrass

Proper grazing rates are extremely important in achieving good weight gains and maintaining a healthy grass stand. The proper stocking rate has been reached when the grass stubble at frost is at 12 inches tall. Grazing below 12 inches can be done if there is enough growing season left for the grasses to regrow to 12 inches after the cattle are removed. That is, the grass must regrow to 12 inches before the first frost. Generally 8 inches of stubble by Sept. 1 will regrow to 12 inches by Nov. 1.

Forage production varies considerably from shallow Ozark soils to deep river-bottom soils. Since the amount of time the pasture will be grazed and the amount of forage produced per acre will vary, the key to determining proper stocking rates is good judgment and experience.

General guidelines have been developed that can assist you for one or two grazing seasons until you can fine-tune your herd’s grazing rates. Resources with these guidelines are provided as links at the bottom of this page.