How do I Seed an Existing Lawn?

Reseeding leads to a lusher lawn.

Seeding over existing lawns helps fill in bald spots and ensures the grass remains lush throughout the yard. Also called renovation, lawn reseeding repairs damage and allows you to plant a grass variety in problem areas that may thrive better than the grass in other parts of the lawn. For example, in shaded areas summer grass doesn't grow well, but cool-season grasses may. Seed cool-season grasses in late summer or early fall and seed warm-season grasses in late spring.

Things You'll Need

• Herbicide
• Dethatching rake
• Lawn aerator
• Fertilizer
• Grass seed
• Seed spreader

Instructions

1. Apply a weed control herbicide two weeks before you plan to seed. Apply either a selective herbicide that kills only broadleaf weeds or a herbicide that kills all existing grass and weeds if you prefer to completely reseed the area.

2. Water the lawn until the top 6 to 8 inches of soil is moist.

3. Rake the lawn with a dethatching rake, removing as much thatch as possible. Thatch is the matted layer of dead plant material on top the soil.

4. Aerate the lawn with a lawn aerator. Pass the aerator over the area you are seeding over three to five times. The aerator opens the soil so moisture and air penetrate to the grass roots better.

5. Apply fertilizer at the rate of ½ lb. of nitrogen per every 1,000 square feet of lawn one day before seeding. Water the area after fertilizing so the fertilizer leaches into the grass root zone.

6. Place grass seed in a drop spreader. Set the seeding rate on the spreader to the amount recommended on the seed package for the particular variety. Push the spreader across the lawn, overlapping each seeding row slightly to ensure the area is completely seeded.

7. Water twice a day, keeping the top 3 inches of soil moist but not soggy. Continue twice daily watering until the grass is 3 to 3 ½ inches tall.

Tips & Warnings

• Allow the new grass to become well established before mowing. Cut it only after it is more than 3 inches tall and cut it no shorter than 2 inches.

• Rent dethatching rakes and aerators from most hardware or home improvement stores.

References

• Colorado State Extension: Renovating the Home Lawn
• University of Minnesota Extension: Lawn Renovation