What Time of the Year to Grow Grass?

Cool-season Grass

• Cool-season grasses thrive when temperatures average 65 to 75 degrees Fahrenheit. These species, which include orchardgrass, fescue and ryegrass, require large amounts of nitrogen fertilization for best growth. Because they use a form of photosynthesis that releases a relatively large amount of carbon dioxide through photorespiration, they tend to go dormant with rising temperatures. Heat increases the rate of photorespiration and loss of carbon dioxide within the plant.

Warm-season Grass

• Warm-season grasses use a different chemical process for photosynthesis. This process uses nitrogen efficiently and reduces the amount of carbon dioxide lost through photorespiration. Sufficient water is required to sustain growth, and these grasses do not grow well when day lengths shorten. They are also lower in protein than cool-season grasses, a major consideration for grazing pastures.

Summertime Considerations

• Drought is the major problem affecting grass during the summer. Without supplemental irrigation, most grass species go dormant during long stretches without rain and may also turn brown. Irrigation is a somewhat controversial practice, however, especially in areas with limited water supplies. If you choose not to water your lawns or pastures during drought periods, they will generally recover on their own once weather conditions improve.

Wintertime Considerations

• In areas where the grass goes dormant during winter, proper management in the autumn can speed spring recovery. Take advantage of the freeze/thaw cycle by adding limestone in the late fall, when winter heaving of the ground can incorporate it more deeply into the soil. Don't mow grass too short right before dormancy occurs. Leave at least 2 inches of leaf and avoid removing more than a third of the blade length when mowing.