Keep in mind when establishing a new lawn by seed (when the entire area is bare ground), it is an excellent time to correct any existing problems. Whether it is drainage, soil pH, soil fertility, or lack of top soil problems, this is the time when it will be the easiest to correct. Survey the site by walking over the area and make note of any potential problem areas that will need to be addressed prior to seeding.
Soil Preparation:
Soil Test. The first step is to have the soil tested. This will determine which nutrients are available in soil, and will provide liming and fertilization recommendations.
Weed Control. Any perennial broadleaf or grassy weeds should be eliminated prior to seeding by properly applying a herbicide such as Roundup. Be sure to follow directions on the herbicide label and check for any restrictions in regards to seeding.
Installation of Irrigation and Drainage. An irrigation system or drainage system, if needed, should be installed prior to top soil preparation. You will be glad in the long run.
Soil Tillage and Grading:
Completely till the soil to a depth of 4 to 6 inches where: 1) the soil compaction is severe; 2) large amounts of phosphorus or lime are recommended; 3) surface drainage is inadequate; or 4) the soil is to be amended.
The subgrade shold slope away from buildings, and the area should be allowed to settle through two or more rains before planting. Low spots where water collects should be filled with additional soil. All building debris, large rock, and rotting wood should be removed from the site.
Lime. Turfgrasses do not perform well in acidic soils. Lime recommendations will be made from the osil test. The lime should be tilled into the soil to a depth of 4 to 6 inches. If soil tests indicate low available magnesium levels, dolomitic limestone should be applied.
Fertilizer. When applying the fertilizer recommended in the soil test, it is beneficial to till in two thirds of the amount to a depth of 4 to 6 inches. The remaining one third should be applied to the surface just prior to seeding, lightly raked into the soil.
Seeding:
Prepare a smooth, firm seedbed. The planting area should be smooth and at your desired level. Distribute the seed evenly. One way to do this is to apply half the seed in one direction and then turn at a right angle and apply the remaining seed over the same area. Lightly cover the seed by raking. Good seed-to-soil contact is critical for adequate germination. If at all possible, the seedbed should then be rolled.
Mulch the area with straw or better yet, one of the new mulches such as Penn Mulch. PennMulch will not blow away as can be the problem with straw. PennMulch also does not need to be removed after the grass has germinated and is ready to mow.
Post-Planting Irrigation:
New seedings require frequent watering to ensure constant surface moisture for 30 days following planting. On hot days, several light waterings may be required during the day.
New Lawn Maintenance:
Begin mowing the new lawn when the grass is one-third taller than the intended mowing height. Be sure the mower blade is sharp. Avoid excessive traffic on a lawn until it is mature. Weed control may be necessary, but do not apply herbicides to new lawns until they have been mowed at least twice.