How to Seed a Lawn
After your final grading you need to rid yourself of any trash, weeds, and any other material that could interfere with the seeding of the lawn. Use a bamboo rake, steel rake or any other type of rake that can rake off stones, sticks, or any other trash that may be in your yard.
Before seeding make sure you have a firm but not a rock solid hard seed bed. A firm seed bed will give your grass a base from which to grow. Soil that is hard as a rock makes seeding a lawn far more difficult. There is place for the roots of your grass to grow if the soil is as hard as concrete.
If the soil is rock hard, it would not hurt to bring in some good top soil to spread over the lawn. Dealing with a heavy clay soil is like seeding into concrete. It makes grass growing far more difficult. Adding organic matter to the soil will help loosen the soil and will give the grass soil it can root into.
(There is a game some builders will do. When the dig the foundation for a house they will strip the lot of good top soil that is on a customer's lot. The builder will then haul the soil away leaving only subsoil from which to grow grass. If you are faced with this situation, it would be better to bring top soil in than to seed a lawn using subsoil as your base.)
If you need to buy top soil buy good screened top soil. This way you avoid clumps, trash, and other debris you can find in unscreened top soil.
Make sure where the top soil came from. In the old days top soil sellers would buy top soil from a farmer. The farmer would be selling off his ground for development. The farmer would be stripping his top soil of the field to sell. The danger in this is if the farmer was growing corn the previous year. There is a chemical that farmers use to suppress grass growth in a farm field. The chemical is Atrazine. If the farmer used the chemical for more than one year, there can be a build up of the chemical in the soil.
If the soil is used to grow grass in a home lawn the following year there is a great danger of lawn failure. As the seed germinates the roots of the grass moves down through the soil profile. If the Atrazine is in the soil as the grass roots moves downward, the roots of the grass plants will come in contact with the Atrazine. When the grass roots absorb the Atrazine that is in the soil, the grass plants will die.
We do not have the farmers or the farm fields as we did years ago. You need to still check from whomever you buy the top soil from. You do not need to spend the money to seed a lawn twice because of the Atrazine in the soil.
Once you have prepared your seedbed, the seeding is rather simple.
Buy or rent a cyclone (broadcast) spreader to seed the lawn. (We do not like drop spreaders. Drop spreaders have a habit of giving the user uneven seed distribution. If any of the holes of the drop seeder have worn or become blocked the seed will not be uniformly distributed) Adjust the spreader to a 40% opening. (On a 1-10 scale set the knob to a scale of 4 to 4 1/2) Put the seed into the hopper and seed.
To make sure that enough seed is applied to the lawn the lawn should be seeded in a checkerboard fashion. The lawn should be seeded first in a north to south pattern. Then the lawn should be seeded going east to west pattern.
No one can walk in a straight line when seeding a lawn. No one can always remember where they have seeded when seeding in just one direction. Seeding in a checkerboard fashion protects the seeder. If the seeded misses seeding in one direction, you can cover the area seeding in the opposite direction.
Seeding rate should be 6 to 8 pounds per 1,000 sq. ft seeding rate. If you seed less than 6 pounds per 1,000 sq. ft. the lawn will come in too thin. Applying more than 8 pounds per 1,000 sq. ft is over seeding the lawn. The only exceptions you make in this rule if the lawn is being planted in late fall. An increased seeding rate will give the seeder an extra edge in germination when the weather is less than perfect for good seed germination.
After seeding you can apply a starter fertilizer to the lawn. The fertilization of the lawn will help with the germination of the grass. Avoid high nitrogen fertilizers when seeding a new lawn. High nitrogen fertilizers can burn the seed. Use low nitrogen fertilizers. Apply a low nitrogen fertilizer with enough phosphate and potash that will promote root growth and cell growth in the new grass plant. (Examples 5-10-10. 10-10- 10, 11-22-6, 10-18-10)
When you have finished seeding and fertilizing, likely rake the seed and the fertilizer into the soil. Just barely cover the seed with the soil. Burying the seed with more than a 1/4 inch of soil will affect the germination of the seed.
Apply enough straw to the soil and to the seed but only lightly. The straw should be applied so that the straw is just barely covering the ground. The seeded should still see the ground after the straw as been applied. If the ground is completely covering the ground, too much straw as been applied! Remove 1/2 of the straw off the ground. Why? Too much straw can choke out the seed as it germinates from the soil.
Straw's purpose is as an erosion control not as a blanket covering of the seed bed. When the straw is applied lightly over the grass area, the straw will keep the soil from moving if there is a rain storm. Straw will also shelter the seed from the hot sun and keep the soil warmer when the lawn is seeded during cool weather. Having a light straw covering makes it easier when it is time to remove the straw. You can remove the straw when you mow the new grass the first time.