Now Is the Best Time to Overseed for a Thicker, Healthier Fall Lawn—How to Do It Right

One of the secrets to successful lawn care is getting the timing right for your lawn chores. From mowing at the right time to raking leaves at the right time, the when is as important as the how. It’s no different with overseeding.

There is a right time to overseed the lawn. Getting it right will give the seed enough time to germinate and the young grass seedlings enough time to become established before harsh weather conditions challenge their viability.

In this article, you will learn why you should overseed a lawn of cool-season grasses in late summer and how to get the job done right, in addition to learning other maintenance tips for maintaining your lawn through summer and transitioning to the fall season.

Why Overseed in Late Summer Instead of Fall

The best time to overseed the lawn is in late summer (provided you’re not having a heat wave) because the weather generally isn’t as hot as in mid-summer, plus the new grass will have plenty of time to grow before it gets cold. Getting the timing right for overseeding in the second half of the year requires a balancing act:

• On the one hand, you must wait to avoid overseeding in extreme heat.
• On the other hand, if you wait too long, the grass may not have time to become established before the cold weather comes.

Even if you can overseed during a mild stretch of weather in late summer, you must keep the lawn properly watered for the grass seedlings to make it.

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How to Overseed Your Lawn the Right Way

You can avoid certain lawn problems simply by having a thick, lush lawn. For example, weeds will exploit bare patches in the lawn that pop up during a hot, dry summer. If allowed to reseed, you may end up battling those weeds for years to come. But weeds have more trouble getting established in a lawn that is thick and lush. If a bare patch does develop, sow it with grass seed before weeds can exploit it. Better yet, overseed your lawn every year so that areas of thinning grass don’t evolve into bare spots.

Assuming your lawn is healthy, overseeding is easy. Here’s how to do it:

1. Select the right kind of grass seed.
2. Mow the lawn shorter (1.5 to 2 inches tall) than you usually do.
3. Using a spreader, spread the seed across the lawn in a checkerboard pattern. This means first pushing the spreader north to south, turning around, and pushing it south to north, and so on, until you’ve covered the whole lawn; then dropping seed east to west and west to east, once again covering the whole lawn. This pattern provides better coverage.
4. Apply a starter fertilizer.
5. If you have overseeded any bare spots, it will be easy for birds to see the seed. To prevent them from eating it, lay down a thin layer of straw.
6. Keep the soil evenly moist until the grass seedlings are established.
7. Avoid walking on the lawn, if you can, until the seedlings become established.
8. Five weeks after germination, apply a quick-release nitrogen fertilizer.

3 Summer-to-Fall Lawn Maintenance Tips

As you transition from summer to fall, lawn care will change in some ways (such as the need to rake leaves off the lawn). But there will be a certain continuity in other ways:

• Continue to water the lawn: Keeping the grass properly watered in fall will help it get through the winter in better shape.
• Continue to feed the lawn: Apply a winterizer fertilizer right after the grass stops actively growing in fall, but while it’s still green.
• Continue to mow the lawn: Mow the lawn throughout the fall until it stops actively growing.