The latter half of August through the middle of September is the best time to seed a lawn in Minnesota. It is easier to keep the germinating seedlings moist, few weeds germinate during this period, and there is sufficient time for the grass plants to develop enough to survive the winter. Favorable results can also be obtained in the spring if proper care is provided.
PREPARING THE SITE:
1. Test the soil for fertility. Homeowners can do this with a purchased kit or a soil sample can be sent to the University of Minnesota for a small fee.
2. Remove existing weeds by spraying with RoundUp or Weed-Out Plus. Read and follow label directions carefully as both products will kill all vegetation. You can reseed 7-10 days after application. If you need to till, wait 2 weeks after application to reseed.
3. Rough grade the area. Remove all debris and stones. Till the soil if it is compacted. If soil amendments are used (peat moss, black soil, etc.), incorporate those amendments into the existing soil. For example, don’t put good black soil in a layer on top of heavy clay. The interface between the two will be very difficulty for grass roots to penetrate. By mixing the amendments into the existing soil, the interface will be blended, grass roots will penetrate to the necessary depth, and your grass will be less susceptible to disease.
4. Lime if a soil test indicates the need. Fertilize with a high phosphorous lawn starter fertilizer. Work these materials into the top 4”-6” of the soil.
5. Fine grade the area by raking just prior to seeding.
1. Purchase seed which is well suited to your particular area (i.e., sun, shade, high traffic).
2. Scatter the seed by hand or by using a spreader. Scatter half the seed in one direction and the rest at a 90 degree angle for more even distribution.
3. Rake very lightly to cover the seed (no more that 1/4”).
4. Mulch if necessary. Slopes or areas where you cannot water would benefit from a light mulch of clean straw. Some soil should show through the straw.
POST SEEDING CARE:
1. Water, water, water. Never allow the germinating seedlings to dry out. Light, frequent sprinklings are necessary from the planting date through several weeks after the grass has germinated. Germination itself can take up to two weeks. As the grass matures, less frequent, but deeper, waterings are the norm.
2. Keep all unnecessary foot traffic off the new grass for several months.
3. Start mowing when grass has reached a height of 3”. Don’t take off more than 1” of leaf height at one time.
4. Do not apply weed killers before or after seeding, unless the product specifically says it can be used during seeding. This is especially true with pre-emergent crabgrass killers.
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