When To Plant Prairiegrasses
Warm-season native grass seeds germinate at a minimum soil temperature of 60 degrees -- usually around April 1 to May 15 depending on location -- which allows weed treatment for seeding into a clean seedbed.
In years of adequate rainfall, or if irrigation is available, stands may be established as late as Aug. 1 in the Midwest. WSGs should have at least 60 days of growth before a frost to protect them from winter injury.
Dormant seeding is possible by seeding in the very late fall, after the soil is too cold for the seed to germinate. In the Midwest, this is usually around November 1. Dormant seeding in late fall offers natural stratification in the soil over winter and also reduces spring workload. This method has additional risks that can cause failure, however, because of weed competition during early spring. Weedy perennials can be eradicated in the fall, but any seeds in the ground will germinate in the spring. This seeding period can be very successful but requires planning ahead to help reduce the potential for weeds to be a significant problem.
Late spring/early summer planting allows weed problems to be eliminated prior to planting, leading to more successful seedings. In most cases, a late spring planting is recommended for WSGs.