How to Grow Grass in Wisconsin Soil. If you live in a colder climate, like Wisconsin, the growing season for grass lawns is shorter than in many other climates. Having a green lawn is not without some difficulties and will need your attention.
Check your soil. Whether you are starting a lawn or patching it, one of the most important things to have is good, dark topsoil. The darker the soil, the richer in nutrients it is. Much of Wisconsin soil is heavy in clay and may need to be adjusted to provide the best base for your new lawn. This can be done by spreading good, dark topsoil over the soil you have and raking it in to mix the newly added ground with what you already have. Spread it evenly, eliminating any holes, rocks and twigs before planting your seed.
Spread your seed. Choose the seed that best meets your sun conditions. There are different seed types for different conditions, ranging from full sun to full shade. If planting in late summer or early fall, mix some winter rye or winter wheat seed with your choice. These seeds come up quickly in spring, provide additional nutrients to the soil and protect your new grass from winter damage. Gently rake the seed into the soil. Come spring, watch where the grass comes up so that it can be repaired easily with additional seed.
Sprinkle your new lawn nightly with a low "soft rain" setting. The ground should be wet but not soaked. As in many parts of the country, Wisconsin can suffer from summer droughts. This will inevitably turn your lawn brown. Note any watering restrictions your location may be under and abide by the rules. Your lawn needs the best start possible so that it can be well-established before the winter snow covers it.
Cut your lawn for the first time after it has been growing at least 1 month. Fertilize lightly with 10-10-10 fertilizer after 2 months (according to package directions). If planting in late fall, spread the fertilizer in spring instead, waiting until spring growth is at least 3 inches high. Once your lawn is established, further fertilizing can be done in fall to provide "winterizing" for your grass. This late-fall fertilizing gives it a much-needed boost of food for the long winter months. Refrain from cutting the lawn after the end of October since the longer growth will help to protect it from the cold.