Overseeding a Lawn: What It Is & How to Do It

While many homeowners think of spring as the best time to fertilize, feed, and take care of their lawn, did you know that proper fall lawn care is the most important step to a healthy, year-round lawn? If you haven’t fertilized regularly during the summer - and let’s be honest, despite our great intentions in spring, we’ve probably missed a couple of feedings - your lawn is likely starved and/or thirsty from the higher temperatures and lower rainfall levels from the summer, and it needs strengthened before the harsh winter months hit. The key to fall lawn care is overseeding, which consists of aerating, seeding, and fertilizing your lawn.

What is Overseeding a Lawn?

Overseeding is the process of planting grass seed on top of your existing lawn without tearing up the grass or soil. Overseeding helps fill in bare patches in your lawn and makes your lawn more dense. The process makes your lawn stronger and healthier, so it’s best to overseed your entire lawn rather than just filling in the bare patches. It also chokes out weeds and helps your lawn resist extremes in temperature and weather.

Overseeding can enhance your lawn's color and texture, giving it a richer appearance. This is beneficial for older, beat up lawns that may have become patchy or discolored due to wear and tear. Overseeding is typically done in the fall when conditions are best for seed germination and helps ensure that your lawn is vibrant, thick, and healthy year after year.

When Should You Overseed Your Lawn?

Overseeding your lawn in the fall is one of the best steps you can take to ensure a healthy lawn throughout the year. Fall provides the ideal conditions for grass seed growth, making it the perfect time to thicken up your lawn. Here are some key reasons why you should overseed your lawn in fall:

Rain and soil moisture are often better in autumn: The increased rainfall in fall helps maintain consistent soil moisture levels, which is essential for seed growth and early root development.
Soil temperatures are warm, air temperature is cool: Warm soil temperatures help seeds grow quickly, while cooler air temperatures reduce stress on youth grass seedlings.
Gets rid of summer weeds: Fall overseeding can help eliminate summer weeds as they begin to die off with the cooling temperatures. New grass has less competition from these weeds, allowing it to crowd out potential weed growth in the future.
Strengthens your lawn before winter: A strong lawn with a dense root system is more likely to survive the cold, dry conditions of winter. Overseeding in the fall gives your grass the time it needs to develop a strong foundation that will help it withstand the winter.
It gives your lawn a head start for next spring: By overseeding in the fall, you allow new grass to establish itself before winter, leading to quicker growth in the spring. This head start means your lawn will be thicker, greener, and healthier when spring arrives.

How to Overseed a Lawn

1. Mow & Rake Your Lawn

Cut your grass on a low setting and rake up all the grass clippings once you're done. This is done so that seeds can contact the soil easier and so that sunlight and water can reach the new seeds.

2. Aerate the Soil

Aeration allows moisture, air, and nutrients to reach deep down to the roots of your grass to boost the overall growth and health of your lawn. The process requires renting a lawn aerator, a self-propelled, walk-behind machine that you push back and forth across your lawn. The aerator punches small holes in your lawn and pulls out plugs of soil, leaving behind pockets where grass seed, water, and nutrients can collect at the base of your lawn’s roots. For more details read How to Aerate Your Lawn

3. Overseed the Lawn

After aerating the soil, apply the grass seed using a spreader to make sure you cover the entire lawn. Choose a high-quality seed blend suited to your region and existing grass type for the best results. For better and faster growth, lightly rake the lawn after spreading the seed, as this helps the seeds settle into the aeration holes and soil.

4. Fertilize

Adding fertilizer to your recently-aerated and seeded lawn helps boost grass growth and provides additional nutrients like nitrogen and phosphorus. Many professionals recommend avoiding weed & feed formulas; the pre-emergent herbicides can limit seed germination.

5. Add Water

Water is essential for any lawn, but recently seeded lawns need consistent moisture for the next 5-10 days. You can water lightly for the first few days after seeding, but after about four days begin alternating between light watering and heavy soaking of the lawn.

Is Overseeding Worth it? - The Benefits

Overseeding is a highly effective lawn care practice that offers numerous benefits, making it well worth the time and effort. By overseeding your lawn, you not only improve its appearance but also improve its overall health and strength. Here are some of the main benefits of overseeding your lawn in fall:

Thickens Your Lawn: Overseeding fills in thin or bare areas and resulting in a denser, more uniform lawn. It also makes it more resistant to wear and tear.
Reduces Weeds: A thick, healthy lawn from overseeding is less likely to be invaded by weeds. The increased grass density crowds out weed seeds.
Head Start in Spring: Overseeding in fall allows your lawn to get a head start in spring, resulting in a faster growing and healthier lawn when spring rolls around.
Improves Disease Resistance: Seeding new, disease-resistant grass varieties through overseeding helps your lawn combat common lawn diseases.
Enhances Drought Tolerance: By overseeding with drought-resistant grass types, your lawn becomes better suited to survive dry conditions.

Schedule to Overseeding in Fall

No matter where you are in the country, you can follow these general guidelines for your overseeding schedule.

Early Fall

As summer begins to fade and overnight temperatures start to cool down, you'll want to begin to address bare or thin spots in your yard. By loosening the soil in these spots and adding grass seed and fall fertilizer, you can help repair your lawn exactly where it's needed.

Mid-Fall

Mid-fall is the perfect time to start the overseeding process that we've outlined above. The cooler temperatures boost fall grass growth, so you'll want to aerate, seed, and fertilize to get the most out of the last good growing season of the year!

Late Fall

As temperatures drop, you'll see more and more leaves start to fall. Make sure to rake and bag leaves quickly, as debris on your lawn can prevent moisture and sunlight from reaching your grass and its roots. A mulching mower or handheld blower are great tools to have for this process!

Properly overseeding your lawn this fall may be the difference between a healthy lawn that comes right back to life in the spring and one that requires a lot of work to get back into shape once winter is over. By mowing, aerating, seeding, fertilizing, and watering at the proper time this fall, you can ensure that your lawn remains healthy all year long.

Overseeding a Lawn: What It Is & How to Do It

What is Overseeding a Lawn?

When Should You Overseed Your Lawn?