How to Overseed a Thin Lawn

Reinvigorate Your Lawn

Is your lawn looking weak and thin? Overseeding can help you get back to the thick, lush, green lawn you're looking to achieve. By spreading grass seed over your existing lawn, you can thicken up the thin areas and get your lawn looking terrific again. (This is different from reseeding, which is when you start over and plant a completely new lawn.)

When to Overseed

In the North, the best time to overseed your lawn is in the fall, when the soil is still warm but the air is cooler and there are fewer weeds for new grass to compete against. Since your trees are starting to shed their leaves, there's plenty of sunlight. However, if you are unable to overseed in the fall, your next best option is the spring. If you live in the South, the best time for overseeding is late spring through mid-summer, since warm-season grasses need warmer soil temperatures to germinate.

Why Overseed?

Over time, grass gets old and needs to be replaced. Worn-out lawns invite weeds. Overseeding is a fast, inexpensive way to help bring your lawn back to its lush, green self without tearing everything out and starting over.

1. Mow Low

Before overseeding your thin lawn, cut your grass shorter than normal and bag the clippings. After mowing, rake the lawn to help loosen the top layer of soil and remove any dead grass and debris. This will give the grass seed easy access to the soil so it can root more easily after germinating.

2. Choose a Grass Seed

The type of grass seed you should choose depends on your existing grass type. If you don't know what type of grass you have, start by consulting our Identifying Your Lawn's Grass Type guide or visit your local garden center where they can help you choose the right Scotts® Grass Seed for your lawn.

If your lawn consists of cool-season grasses, choose a product specially designed to thicken thin lawns, such as Scotts® Turf Builder® Thick'R Lawn® Sun & Shade, which combines grass seed, fertilizer, and a soil improver into one easy-to-use product you apply with a spreader.

If your lawn has a warm-season grass, Scotts® Turf Builder® Thick'R Lawn® Tall Fescue Mix or Scotts® Turf Builder® Thick'R Lawn® Bermudagrass are great options, depending on which grass type you have in your lawn.

3. Improve the Soil

If you're using a grass seed product such as Scotts® Turf Builder® Rapid Grass Sun & Shade Mix® to overseed your lawn instead of Scotts® Turf Builder® Thick'R Lawn®, it's a good idea to rake in a thin, 0.25-inch layer of enriched soil over your lawn prior to application to help the seed settle in. Don't put so much down that you kill your existing grass; less than a quarter of an inch is plenty. Scotts® Turf Builder® LawnSoil™ works well for this purpose.

4. Spread the Seed

You've cut the lawn short, raked it, and removed any debris, and now comes the easiest part of the overseeding process. Just fill up your spreader, adjust the setting according to the label directions, and apply. Don't have a spreader yet? The Scotts® Whirl™ Hand-Powered Spreader is an excellent choice for small lawns—it's simple to use and spreads product quite smoothly. For larger lawns, Scotts® Turf Builder® EdgeGuard® DLX Broadcast Spreader is a great option, or check out How to Choose Lawn Products and Spreaders for the best spreader recommendation for your yard.

5. Feed and Water

To give your new grass seedlings the essential nutrients they need for fast growth, apply Scotts® Turf Builder® Starter® Food for New Grass after you've spread the grass seed. No need to do this with Scotts® Turf Builder® Thick'R Lawn® since it already contains all the nutrients your new grass needs. Afterward, no matter which product you used to overseed, be sure to keep the soil consistently moist by lightly watering once or twice a day until the seedlings have reached the height of the rest of your lawn.