Overseeding in the fall can keep your lawn looking full and lush come the spring.
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When done correctly, overseeding a lawn can provide a healthy and lush lawn. Knowing your grass variety, and the proper steps to take, helps create results.
There are two different reasons for overseeding in the fall.
Cool season grass (Kentucky bluegrass, perennial ryegrass, or tall fescue) is overseeded to maintain the thickness of a lawn, especially if it has thinned due to summer heat.
Warm season grass (bermudagrass or buffalograss) is overseeded with perennial ryegrass, a cool season variety, when the warm season grass becomes dormant right before winter. This creates a green lawn all year round.
The method for overseeding both kinds of lawns with cool season grass seeds is the same. Below are some tips to help you use that method successfully.
1. Overseed at the right time
Cool season seeds germinate when air temperatures are about 60 to 75°F, and when soil temperatures are about 50 to 55°F. Planting too early or too late in the season will lengthen the time it takes for the seeds to germinate, or prevent them from germinating at all.
2. Aerate if needed
If your soil is compacted, you should aerate the soil before you plant the new seeds. Pulling out plugs of soil is stressful to an established lawn and therefore would be devastating to new seedlings. An aerated soil also has the benefit of new spaces for seeds to grow in.
3. Choose the right grass seed
You can choose seed that matches the cool season species in your lawn, but you could also introduce a new variety, which would increase your lawn’s tolerance to drought and disease.
Perennial ryegrass is the only option for overseeding warm season lawns because it germinates quickly and has unfavorable conditions to compete with come spring, when the warm season grass begins growing again. Pick a grass seed with a high pure live seed rate, a high germination rate, and no weeds or filler material.
4. Mow the lawn
Before you overseed, mow the lawn very short, almost to the point of scalping it. When the seeds start growing, you will want them to have enough access to sunlight, and taller grass can block much of it.
5. Use the recommended amount of seed
Sow the recommended amount of seed split in a horizontal and then vertical direction across the lawn. There should be recommendations of what rate to overseed at on the bag. You can sow by hand or with a seed spreader.
6. Rake after overseeding
Good soil and seed contact is vital to the germination process. For this reason you should rake the lawn lightly after you’ve overseeded. You could also add a 1/8-inch layer of topsoil and firm it with a roller, although it’s not necessary.
7. Water correctly
After the seeds have been planted, keep the soil lightly moist by watering briefly and frequently several times a day. If the soil is too dry, the seeds could die before germinating. If the soil is too wet, they could get washed away. Once the new grass is visible you can switch to watering deeply and infrequently.
Rob Wendell is the chief executive officer and director of Granite Seed Company, supplier of premier seed and erosion control products to commercial customers and government agencies. Rob led the launch of NaturesFinestSeed.com, a division of Granite Seed focused on bringing superior seed products to consumers nationwide.
FAQs
Avoid weed & feed products; the pre-emergent herbicides inhibit seed germination. Starter fertilizer, such as Pennington Ultragreen Starter Fertilizer 12-22-8, delivers essential nutrients for new grass. Phosphorus supports vigorous root growth, while nitrogen fuels top growth and greening.
What is the best way to overseed grass in the fall? ›
Why Overseed in the Fall?
- Measure Your Lawn.
- Choose Your Grass Seed.
- Mow the Lawn Short.
- Scratch Bare Spots.
- Spread the Grass Seed.
- Feed the Lawn.
- Cover the Bare Spots.
- Water New Seed.
Avoid weed & feed products; the pre-emergent herbicides inhibit seed germination. Starter fertilizer, such as Pennington Ultragreen Starter Fertilizer 12-22-8, delivers essential nutrients for new grass. Phosphorus supports vigorous root growth, while nitrogen fuels top growth and greening.
What are the steps for overseeding? ›
- Step One: Mow and Rake. Begin the overseeding process by mowing your lawn on the lowest setting and bagging the clippings. ...
- Step Two: Amend the Soil. ...
- Step Three: Add the Seeds. ...
- Step Four: Feed the Grass. ...
- Step Five: Water the Lawn.
The goal is to keep the top ½ inch of soil moist for at least two to three weeks. After then, watering may be cut back to once a day or every other day, again depending on weather and watering times.
What to cover grass seed with when overseeding? ›
If you're using grass seed 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 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.
What is the best grass seed for overseeding in the fall? ›
Cool-season grasses like Kentucky bluegrass and tall fescue are more favorable for growth in cooler temperatures from August to early November. In conjunction with less weed competition, this allows more timing and is preferred for growth in the fall for cool-season grasses than in the spring.
Should I fertilize right after overseeding? ›
Your best bet is to fertilize your newly seeded or overseeded lawn with Scotts® Turf Builder® Starter® Food for New Grass directly after seeding. Then, you need to wait 6 to 8 weeks before fertilizing again.
Can I overseed and fertilize at the same time in the fall? ›
You may choose to use fertilizer when overseeding your lawn. Fertilizer delivers nutrients essential to young growing grass and optimizes seed germination and quick establishment. The best time to fertilize your yard is right after your aerate it and spread your seeds.
Should I overseed twice in fall? ›
It is recommended to fill in a lawn with 50% or more grass coverage. However, at 50% you will likely need overseeding twice to get the lawn to 90-100%. Just throwing seed on your lawn without aerating or working up the soil will have little to no positive effect on your lawn.
How to prepare your lawn for overseeding
- Choose the right time of year to overseed your lawn. ...
- Mow the lawn before you start the overseeding process. ...
- Water the lawn enough to moisten the soil but don't saturate it. ...
- Aerate the soil before overseeding. ...
- Fertilize your lawn after aeration.
Water the lawn to moisten the soil, but make sure it's not soaking wet. A good rule of thumb is to water the day before you plan to overseed so the soil has a little time to dry.
Can you walk on grass when overseeding? ›
However, if you did not have any existing grass and this is a new lawn installation we recommend that you keep heavy equipment and foot traffic off the areas that had seed spread for the first six weeks. After that time you can begin mowing the grass.
Is it OK if it rains after overseeding? ›
Taking the necessary short and long term aftercare of seed and baby grass is an important consideration when determining how to overseed a lawn, but heavy rain after seeding can throw off all of the best laid plans.
What happens if you don't water after overseeding? ›
During this time, it's critical that you water your lawn, and once you start watering, it needs to be consistently continued. If you stop watering your lawn, the new grass could dry out and die.
What temperature should I overseed in the fall? ›
1. Overseed at the right time. Cool season seeds germinate when air temperatures are about 60 to 75°F, and when soil temperatures are about 50 to 55°F. Planting too early or too late in the season will lengthen the time it takes for the seeds to germinate, or prevent them from germinating at all.
Can I overseed without aerating? ›
Can I overseed my lawn without aerating? Yes, you can overseed your lawn without aerating it, but results may vary. If you have the time, dethatching or aerating your lawn before overseeding will yield the best results. Overseeding your lawn without aerating will work, but less seed will take root.
How late in the fall can you overseed? ›
When it's October, people often wonder if it is too late to plant new seed. The good news is if you hurry, seed can still be planted in October with the hope that it will survive the upcoming winter. Although September is the best time, often we can still plant grass seed up to October 15 with good results.
Does grass seed need to be watered in the fall? ›
Watering Thoroughly, but Not Too Much
Once the seeds have been properly sown and lightly incorporated into the existing soil, water the area thoroughly and leave until next spring. By this time of year, our cool to cold temperatures and short days will help keep the areas moist far longer than in summer.
Should I overseed my lawn before or after rain? ›
Best practice is to avoid overseeding a soggy lawn. Instead, wait for the lawn to dry, and check to make sure there's no rain in the immediate forecast when you plan to seed. Then, properly prepare your lawn for overseeding so the seed can establish itself before any upcoming rainstorms.
