First step in planting lawn seeds is determining which seeds to plant. Besides selecting a grass type that is appropriate for your geographic / climatic conditions, it is imperative to plant blends. There is no perfect grass for all conditions. Blends of grass will address a range of conditions. Having diversity is essential for successful seeding. Using 100% of anything is a mistake. If a disease or insect comes along that attacks one particular variety, the others should remain in tact.
Buy the best seed possible. Before you buy a bag or box of grass seed, read the label carefully. A label can tell you about the quality of the seed. Poor-quality seed takes just as much work to sow as good quality seed.
Mixes that contain more than 15% annual ryegrass or annual bluegrass are generally of poor quality
Look for germination percentages above 85%. Check the date is was tested and only buy seed tested within the last year
Best mixes have less than 1% "other crop" seed listed. Should contain no annual and rough bluegrass (poa annua and P.trivalis) and no bentgrass.
Producers list %s for noxious and non-noxious weeds. Buy mixes that contain NO noxious weed seeds. Non noxious seeds are very difficult to remove entirely (should contain somewhere between 0.3% - 0.5% by weight.
Inert matter includes things like broken seeds that will not germinate and other fillers. This should be well below 1%.
Next and more important is soil preparation. While seeds can sprout in almost any soil, a strong healthy grass needs a good soil preparation to give the new plants the best chance of success.
Rake out the soil and get the soil loose so the seed can penetrate the soil and get the best contact. This will help get the roots off to a good start.
Control perennial weeds such as quackgrass, tall fescue and bentgrass.
Remove existing sod. Modify the soil if necessary.
Rough grade the lawn area. Allow the soil to settle and re-grade, if necessary.
Have soil tested. Apply corrective quantities of fertilizer and lime, if needed.
Rototill or otherwise till the soil 3" - 6" deep.
Remove stones, wood and other debris from the top 3" - 6" of the soil.
Allow soil to settle, or firm with a heavy roller.
Apply starter fertilizer and rake it in while removing stones, trash, and other foreign material. Fill in any small depressions that are present.
Seed or sod,—if sod, ignore items 10 and 11.
Rake lightly-let some seed remain on surface.
Irrigate. Surface must be kept moist until seedlings establish.
Sow seed evenly with a spreader. Plan to go over the area to be seeded twice, preferably in a different direction each time. With a low seeding rate, it is easier to get good distribution if something is added to the seed to make more bulk. Several materials such as sand or corn meal may be used. Starter fertilizer should be applied just prior to or after seeding.
The soil should be raked lightly to cover the seed with 0.1" - 0.3" of soil. If some seed can still be seen after raking, they have not been covered too deeply.
On terrace slopes where erosion may be a problem, stake down burlap, cheesecloth, special netting, or other very thin cloth through which the grass can sprout (preferably bio-degradable). After establishment you do not need to remove this cloth.
A light lawn roller should be used to roll the mulch after it is applied, providing the soil is not too wet. The lawn should be irrigated and the surface kept moist. This usually means sprinkling the new seeding lightly at least twice a day, sometimes more often, depending on how hot the weather is and how often it rains. After the seedlings emerge and begin to establish, the interval between watering can be lengthened provided adequate moisture is available for seedling growth.
Don't allow newly seeded grass to grow excessively long before the first mowing. If the grass gets too tall before mowing and you mow more than the 1/3 rule, you'll shock the plants, stressing them and slowing the process of forming a healthy lawn.