How to Use a Seed Germination Blanket Over Existing Grass

Seed germination blankets provide a way to re-seed bare spots in the lawn with an increased chance of success. Germination blankets allow light and water to reach seeds underneath them so they will sprout. Blankets also warm the soil to germinate seeds more quickly. Seeds may be washed away by heavy rains, but seed blankets hold the seeds in place so they do not wash into one spot, sprout in clumps and leave other areas bare. A seed blanket also protects seeds and emerging blades so animals and birds do not eat them. These types of blankets can be used in sparse areas over existing grass to help your lawn fill in evenly.

1
Mow your lawn, including the areas that need grass seed and the grass that is growing nearby. Measure the sparse areas that will need grass seed to determine how much seed germination blanketing you will need. Rolls generally come in widths of 4, 6, 8, 12 and 16 feet and in lengths of 20 to 200 yards.
2
Rake the sparse areas with a garden rake to remove any dead grass, grass clippings, stones or rocks. Loosen the soil about 2 inches deep to aerate it. This helps establish grass seeds.
3
Sprinkle grass starter fertilizer on the planting areas according to the package directions. You can sprinkle the fertilizer by hand on small patches or use a broadcaster to feed the entire lawn and rejuvenate the established grass.
4
Place grass seed evenly in the bare spots by hand or use a broadcaster to apply grass seed to larger areas. Follow the package directions on how heavily to spread the seed. Do not over seed areas, as the grass will be uneven and grow in clumps.
5
Lay a seed germination blanket roll on one side of a bare area, about 3 inches from the sparse area. Turn the roll with the beginning edge facing you, laying flat on the ground and the roll facing the bare spot. The thicker netting side that is on the beginning edge near you faces upward. Push the roll across the bare spot to bypass the other side of the bare spot about 3 inches. Cut the excess of the roll off with scissors.
6
Roll out additional lengths of a germination blanket overlapping each length by 3 inches to cover large spots.
7
Insert stakes into the edges of the blanket. Drive them into the lawn with a rubber mallet until they are flush with the ground. Insert stakes surrounding each area and on any overlapping areas at the intervals specified by the manufacturer.
8
Turn on a garden hose and thoroughly soak the blankets. If you have a large area, turn a sprinkler on the area and allow the blankets to become wet to the point of runoff.
9
Water the blankets to keep them thoroughly moist until grass sprouts through the blanket.
10
Allow the grass sprouts to grow to around 2 to 3 inches tall before you mow those areas.

Tips

Choose grass seed that is the same type as your existing grass for a seamless lawn.
Plant cool-weather grasses in early spring or fall. Plant warm-season grasses from the middle of spring until the middle of summer. These planting times allow grass seed to become established more quickly.
Biodegradable blankets and stakes start to break down within about six weeks.
Warnings

Keep your lawnmower blades sharp to prevent tearing grass, which can make the lawn look ragged.
Set your lawnmower blades so you only cut about one-third of the grass length at a time. This keeps your turf looking greener and allows the grass clippings to fall back to the ground and subsequently apply nutrients to the roots

Resources

University of Arkansas Agriculture News: Seed Covers and Germination Blankets Influence the Establishment of Seeded Warm-Season Gra
Merritt Seed: Futerra the Ultimate Blanket
Scotts Miracle-Gro: Scotts Starter Fertilizer