Types

• Grasses are divided into two basic types: warm season and cool season. Pennsylvania's mild climate makes it better-suited for the latter. Cool-season grasses include bluegrass, ryegrass and fescues.
  
  

Fall Planting

• Late summer and early fall are the best times to plant grass in Pennsylvania. Grass seed should be planted between Sept. 1 and Oct. 15 in Southeastern Pennsylvania; Aug. 10 and Sept. 10 in the northern tier and high-altitude counties; and between Aug. 20 and Oct. 1 in other parts of the state, according to Penn State University.
  
  

Spring Planting

• In some cases, additional spring seeding may be necessary. In Southeastern Pennsylvania, finish spring planting before April 1. In the northern tier or high-altitude counties, finish planting before May 20. Elsewhere in the state, spring planting should be done by May 7.