Complete Guide to Overseeding Your Lawn

What is Overseeding?

Many homeowners are unaware of a great lawn hack used by golf courses known as “overseeding.”

Overseeding — which can also be referred to as re-seeding — is a low-cost and effective way to create a beautiful green lawn year-round simply by adding additional seed in the spring or fall. The additional seed thickens your lawn creating a lush turf that especially in warmer climates can even last year-round.

Most grasses have a life cycle of about six weeks during which they must continually reproduce with the new grass blades starting the cycle over again. 

However, over time, grasses will reach maturity and reproduction will slow down. The result is your lawn is thinner and bare patches may start to appear. This problem is even more exacerbated if there is heavy foot traffic. A thinning lawn then becomes vulnerable to weeds and grass diseases.

Overseeding adds in new seed and young grasses to a maturing lawn which eliminates thinning, fills in bare patches, and creates a lush green carpet. In warmer climates where warm-season grasses may turn brown and die off during winter, overseeding can help retain a green lawn through winter.

Pros and Cons of Overseeding Your Lawn

Though overseeding is not as risky as applying fertilizers, herbicides, or insecticides to your lawn, there are still a handful of pros and cons to consider before using this technique on your lawn.  

Pros of Overseeding

Thickens your lawn

One of the main benefits of overseeding is that it thickens your lawn. The new grass seeds that you plant will fill in the bare patches and create a more uniform appearance. This will make your lawn look healthier and more vibrant.

Increases Resistance to Pests and Disease

Overseeding can also help to improve the overall health of your lawn. A thicker lawn is more resistant to pests and disease, which means you’ll spend less time and money on pest control and fertilizers.

Improves Soil Health

When you overseed, you’re not just adding new grass seeds to your lawn. You’re also adding organic matter to the soil, which helps to improve soil health. This can lead to better nutrient retention, improved drainage, and better overall plant growth.

Cost-Effective

Overseeding is a cost-effective way to improve the appearance and health of your lawn. It’s much cheaper than tearing up your lawn and starting from scratch, and it requires less maintenance than constantly repairing bare patches.

Cons of Overseeding

Timing is Important

If you don’t overseed at the right time, your new grass seeds won’t germinate, and you’ll have wasted your time and money. It’s important to overseed when the weather is right and the soil is warm enough for the seeds to germinate.

Requires Proper Preparation

To get the best results from overseeding, you need to properly prepare your lawn. This means aerating the soil, removing any debris, and mowing the grass short before seeding. Failure to do so can result in poor germination rates.

Competition with Existing Grass

When you overseed, you’re introducing new grass seeds that will compete with the existing grass for nutrients and water. If your existing grass is already weak or struggling, overseeding may not be the best option.

Maintenance is Key

Once you’ve overseeded, you need to maintain your lawn properly to get the best results. This includes regular watering, fertilizing, and mowing. If you don’t maintain your lawn properly, your new grass may not thrive, and you’ll have wasted your time and money.

How to Overseed Your Lawn

Overseeding is not a complicated process but does require preparation of the lawn in order for the new seed to contact the soil and take root. Below is an easy 5-step process to overseeding:

Assess Your Lawn Issues

Take time to analyze why your lawn is thinning to be sure you do not have other issues, such as standing water, grass diseases or soil with poor pH or lacking nutrients. Overseeding is ineffective if these issues are present so they must be addressed first.

If your lawn is thinning because grass has matured and other factors such as not mowing properly, high foot traffic, shade or drought/heat stress are at play, overseeding along with proper lawn care may fix the issues.

Pick The Best Time Of Year To Overseed

New seeds require a time of year with warm – not hot – temperatures and plenty of rain or watering as the seed establishes its root system.

In cooler climate areas, lawns should be overseeded with cool-weather grasses such as ryegrass or bluegrass in late summer or early fall. This gives the grass time to build roots before winter and then to build deeper roots the following spring. Homeowners can also choose to overseed in the spring at the last frost date for their area.

In warmer climate areas, lawns planted with warm-weather grasses like bermudagrass ideally should overseed sometime between February and April when temps are in the 70s or low 80s and the lawn is beginning to green up and grow. They can also choose to overseed in the fall as well to create a green lawn through the winter.

Overseeding in the fall is also effective because the warm days and cooler nights along with rain and moisture promote growth in the root system. In addition, the new grass does not have to compete as much with weeds and it can establish a root system in the event spring turns out to be hot and dry.

Prepare Your Lawn For Overseeding

Preparing your lawn to accept the seed requires mowing, dethatching and aerating the soil.

First, mow your lawn at a closer level than normal – preferably between 1 to 2 inches – known as scalping, so that seed can reach the soil.

Second, dethatch the grass using a metal tine rake to pick up grass clippings and debris and to break up the soil surface. Again, this prepares the seed to contact the soil and loosens the soil. 

There are also pull-behind dethatchers for a riding mower with dozens of tines to scrape the soil. The tines need to scratch at least an eighth of an inch into the soil so weight the dethatcher down if needed, then use your mower’s bagger to collect the clippings and debris. 

This dethatching process is particularly important with warm-weather grasses because it cuts through their thicker blades allowing the seed to reach the soil.

Lastly, aerate the soil either by hand or by renting a core aerator from a home improvement store. Note that pull-behind, non-motorized aerators are lighter and easier to use but a large lawn area may require the heavy motorized aerator. 

A core aerator will actually pull out a plug of grass and soil approximately 3 inches long and 1 inch wide as you move – this does not harm your lawn. There are also spike aerators which just punch a hole in the ground and can be towed behind a riding mower.

Be sure to aerate after a heavy rain or heavy watering and make 3-4 passes over the lawn. If working by hand in a small area, move in a different direction with each pass to open holes for the seed in as many places as possible. The aeration of the soil loosens soil, increasing air and water exchange to the roots of the new grass.

Note that you can also rent a seeder that aerates and seeds at the same time but these are best on flat lawns with no holes, dips or rocks. If your lawn has holes and dips the aerating blades will glide over without penetrating the soil or if your lawn is rocky, the rocks will dull the aerating blades.

Buy Quality Seeds

While many places carry seed, beware of budget brand seeds meant more for pasture grass than lawns or which do not match your lawn needs. Many companies produce high quality seed mixes designed for overseeding, so read labels and get advice to find the best seed to fill out your lawn.

Most seed meant for overseeding will be a cold-weather variety of thin fescue but you want to match seeds with what you already have in your lawn. If you have a turf-type tall fescue do not overseed with a coarse type tall fescue like Kentucky 31 or Alta which produces larger and wider blades and is meant more as a pasture grass.

You can combine bluegrass seed with a turf-type tall fescue, but avoid the popular Kentucky bluegrass seed as it cannot handle regular fertilization or high maintenance without becoming diseased. There are improved varieties of Kentucky bluegrass which will do well in most lawns without the drawbacks of the original variety.

Also avoid choosing a shady fine fescue such as creeping red fescue, sheep fescue, etc. These grasses are designed for cold climates and do not like the sun. However, having them as part of a mixed bag of seed is fine.

Another grass type to avoid is the cheap, annual ryegrass which springs up quickly but lasts only a year. It is often found in budget brand seeds. Look instead for perennial ryegrass, but make sure it is mixed with other fescues.

For warm-weather Bermudagrass, choose a variety mix of ryegrass, turf-type fescue and bluegrass and do not mix in a different type of warm-weather grass. Mixing zoysia grass or St. Augustine grass or Bermudagrass together results in grasses competing with each other.

Again, when overseeding, keep to the same type of grass planted in your lawn mixed with a variety of cool-season grass seeds.

Spreading and Caring for Your New Seed

Overseeding is more of a long game plan, and it may take a couple of years before you produce the thick, lush lawn you desire. With this in mind, don’t listen to common advice that you should use twice or three times the amount of seed as you used to establish a lawn as this assumes you will fail to water.

Instead, limit the amount of seed you disburse to approximately 2-4 lbs of seed per 1000 sq ft. or 4-8 lbs if you are covering open ground. Then, cover the seed with a thin layer of soil using a rake.

Water accordingly, by sprinkling the area 2-3 times a day and then watering less frequently but deeper after germination. Be very careful that you are not over soaking roots as it can cause root rot.

You also do not want to mow until the grass has germinated and reached at least 2 inches in height which will take 2-3 weeks time. You can compost or fertilize before or after your seed.

With careful planning and time, overseeding is worth the effort especially when you see your lawn getting thicker, becoming more lush, green and full. 

But if you do lack time for the process, you can always turn to a lawn care professional who can include an annual overseeding into their regular maintenance schedule.

Simply Green’s Seeding and Aeration Service

If you’re like most homeowners, you probably take great pride in your lawn. After all, a well-manicured yard is the first impression guests have of your home. 

That’s why it’s important to make sure your lawn is healthy and looks its best. One way to achieve this is by having Simply Green Lawn Care provide fescue aeration and seeding services, which can help your lawn look its best. Learn more about our lawn aeration services and get in touch with our lawn care team.

Contact us early to schedule your core aeration and fescue seeding by calling 770-923-0387, or click here to request a FREE estimate.