Planting grass seed in the winter is only possible in moderate climates. Grass seed needs warm soil to germinate. Seed should never be planted when there is a possibility of freezing temperatures.
Before planting, be sure to remove all of the weeds and smooth the area with a rake to break up any large clumps. The ground needs to be moist but not muddy. To ensure even coverage, spread the grass seeds twice over the area being planted. For the second scattering of the seeds, spread them at a 90 degree angle relative to the first planting. To cover the seeds with soil, lightly run the back side of a garden rake over the seeds. Grass seed will not grow if it is covered with more than a quarter of an inch of soil. To make sure that the grass seed is firmly held in the soil, roll a lawn roller over the seeds after planting. Cover the seeds with a thin layer of compost, straw or steer manure. Keep the grass seed moist until germination (which can take up to two weeks). Light rain is good for seed germination, but a hard rain cause puddles that displace the seeds.