Maryland' homeowners can enjoy lush, emerald-green lawns each summer if they put in a bit of preparation when planting their grass seed. Soil is an important factor in the success of planting grass seed, timing is another.
Purchase a soil test kit from your local nursery. Maryland soil tends to be more acidic than grass seed prefers, and a quick test will allow you to determine exactly how much lime to add to raise the pH without increasing the risk of disease. Maryland soil also tends toward clay--Bob Wentworth of Wentworth Nursery suggests adding 40 lbs. of gypsum per 1,000 square feet to break up and aerate the soil.
According to the University of Maryland Extension, planting your grass seed between mid-August and late October gives it the best chance of survival. The next-best option is late February through March. These months provide the correct temperatures for seed germination--from 40 to 70 degrees F--along with the likelihood of more rain and less competition from weed seedlings.
Fertilize the soil before planting the seed, then again in late winter. Do not fertilize during the spring or summer, when weeds grow, but fertilize again in the fall to nourish the grass for the winter.