How to Plant Grass Seeds on Existing Lawn? [Complete Overseeding Guide]


how to plant grass seeds on existing lawn

Are you a passionate gardener? Are you observing the thinning of grass and the appearance of bare spots on your lawn? What will you do now?

Does it require overseeding or the renovation of the whole lawn? If yes, you should not panic.

We are going to explain how you can grow grass on your existing lawn in this article. Don’t go away, read it till the end. You will surely find the solution for your problematic lawn.

How to plant grass seeds on the existing lawn? Overseeding on the existing lawn requires well-prepared soil. It is done by mowing the existing grass and dethatching the lawn. Aeration and fertilizing soil are also critical. After you plant the new seeds, keeping the grass bed moist is necessary for germination. The sprouts may require 2 weeks to appear. You can mow your lawn after the new grass reaches the height of the old grass.

No doubt, a super lush green lawn is always attractive to the visitors at first glance. Obviously, it requires a lot of time and effort to maintain a healthy garden. If you are caring for your garden properly, it can be really disturbing. Such lawn gives the same feeling of grief that a person may experience after observing bald patches on his head. Doesn’t it sound funny? At the same time, it feels sad.

How Do You Overseed An Existing Lawn?

Do you know that overseeding can refill the bare patches of your garden? Have you any idea what is overseeding? Let’s explain how to plant a new lawn over an old lawn.

If the grass in your garden is thinning, it needs the sowing of new seeds over the existing lawn. This process is named overseeding. In fact, the grass in your garden is exposed to sunlight, extremely high and low temperatures, rain, and snowfall. Even if you are watering, fertilizing, and mowing regularly, the thinning of grass is natural because of exposure to weather elements.

To fill any bare patches, overseeding is an easy and quick way. It not only enhances the overall look of your lawn but also gives luster and strength to the grass. It takes nearly eight weeks to establish a graceful lawn.

But before we go towards the procedure, it is critical to consider the type of grass that is better suited for your lawn concerning the climate. After reading, you will decide if your lawn needs renovation or only overseeding will solve the problem. Plus, this info will also be helpful if you are planting new grass seeds in your garden for the first time.

So, here we go!

Choice Of the Grass With Climate

If you are establishing a lush beautiful lawn, you will not succeed unless you choose the best grass that can cope with the harsh elements of weather in that climate.

 The premium lawn grasses are designed specifically for certain factors in a region that matters. These factors include dryness or fertility, altitude, and moisture of an area.

 For the regions with cool spring, fall season, and moderate summer, cool-season grasses are better suited. However, for the areas where summer temperatures are very high, warm-season grass flourish well.

Advantages Of The Overseeding

Overseeding can do wonders for your garden. It only requires your attention and your garden will surprise everyone. So, let’s figure out the advantages of the overseeding.

  • Overseeding gives robustness to your yard.
  • As a result of dethatching, the soil gets proper sunlight and air.
  • It helps in controlling pests and fungus.
  • It improves the drought tolerance of grass.
  • A healthy lawn gives you freshness.

For your convenience, we have explained cool and warm-season grasses in detail. So, you can select the best one.

Cold Season Grass

Have you any idea which grasses grow well in the cool season? Well, the cool-season grasses include ryegrasses, fescues(tall fescue and fine fescue), and bluegrasses(Kentucky bluegrass).

 These grasses flourish well in the northeast and midwestern region of the United States. Midwest eastern states have similar humidity to northeastern regions but western states have an arid atmosphere. For the Pacific Northwest region lawns, bluegrasses, and tall fescues are ideal.

Due to low temperatures in summer and winters and a highly humid environment, these grasses have a natural resistance to diseases that mostly occur in a cool climate. Amongst these grasses, Kentucky bluegrass is ideal for all the northeast regions of the U.S.

 Though lack of water induces dormancy in this grass, still it can regain strength with watering. However, sometimes ryegrass is also blended with Kentucky bluegrass and grows really well to provide a full green grass bed.

Here are some important points about cool-season grass. Let’s have a look to learn more:

  • The best sowing time for cool-season grass is from mid-August through mid-October.
  • It can flourish well in the cooler regions even at freezing temperatures.
  • It grows in spring and fall and goes dormant in summer.
  • Its thriving temperature is 16 degrees celsius.
  • These grasses have fine longer blades and require mowing frequently.

Warm-season grasses

The southeast region of the U.S stretching from the Atlantic coast into Texas has a hot and humid climate. For the southeast lawn, warm-season grasses are suitable. These grasses include Bahia, Bermuda, centipede, St. Augustine, and Zoysia.

For the southwest region of the U.S, Bermuda grass is ideal as it is well-tolerated to heat, salt, and drought. It grows relatively faster and produces a thick dark green grass bed. It becomes dormant when the temperature falls below 4 degrees Celsius.

For the lawns of the deep south and Gulf Coast regions, Bahia grass thrives better. It grows slowly with medium texture and light green in color. It has no dormant period and stays green throughout the year. The best thing is it can withstand drought and foot traffic.

Here are certain important points for warm-season grasses. So, have a look to increase your knowledge:

  • The best sowing time for warm-season grasses is from March through September.
  • These grasses grow during summer and mild winters.
  • It grows well in the temperature above 26 degrees celsius and goes dormant in winter.
  • Homeowners often overseed these grasses throughout the year to maintain a lush green grass bed.
  • Warm-season grasses can withstand drought due to less water requirement to thrive.
  • Having coarse and wide blades, these grasses are mowed closer to the ground.

Grasses For Transition regions

The area covering the Central states of the U.S ranging from the Atlantic Coast west through Kansas is the transition region. The winter here is extreme and summer is quite hot providing a challenging climate for the survival of grasses.

For transition zones, tall fescue grows well because it is low maintenance, heat-tolerant grass. Its roots grow deeply providing heat protection and coping drought conditions.

Zoysia grass is also extensively used in the transition region. It is naturally resistant to disease and pests. Moreover, it requires low maintenance and also long-lasting as compared to the other warm-season grasses.

Stepwise Procedure Of Overseeding

Hopefully, now you better understand which grass will grow well on your own depending on the climate of the region.

You might be wondering about the procedure of overseeding. Don’t be concerned, it is quite easy. You just need to follow the steps mentioned below. So, have a look to know what are these:

Step 1: Considerations Before Overseeding

Before overseeding your lawn, it is critical to keep the following considerations in mind:

  • Firstly, make sure to check what is the actual cause of bare spots.
  • If your lawn is facing soil compaction, poor sunlight, poor soil conditions, and fungus try to solve these problems first. Use a fungicide to fix the fungus.
  • Make sure to select the best grass seeds matching with the climate of your region.
  • If you cannot guess the problem, take the help of a professional, otherwise, all of your efforts will go in vain.
  • Check the quality of soil, as some grasses grow only in neutral soils.
  • Don’t use the weed killer before overseeding as it will kill the newly germinated plants.
  • If you observe any pest, fix that before you start overseeding.
  • If your lawn faces a lot of foot traffic, you should select the grass seeds with high foot traffic tolerance.

Step 2: Get Your Lawn Ready For Overseeding

Before you start overseeding, it is very important to prepare the lawn. You just need to follow the simple and easy points mentioned below:

Watering: Deeply water the lawn before mowing even if you are planting a new garden or overseeding. For the whole renovation of the lawn, it is recommended to dig the ground to 3 inches. You can use a sprinkler system or lawn watering kit.

Mowing: If the grass in your lawn is longer than 2 inches, cut it short to a height of 2 inches using a lawnmower. Bag or rake the clippings. It’s better to set the mower to the lowest setting while mowing.

Dethatching the soil: A dead turfgrass tissue that accumulates on the surface of the soil is called thatch and its mechanical removal is known as dethatching. After mowing, dethatch the accumulated layer of dead grass over the soil by using a dethatcher pulled behind a riding mower.

Aeration: Next step is to aerate your lawn by using a plug or spike aerator. If there is any compact soil, break it down to ensure the proper oxygen and nutrient flow.

Fertilizer: After aeration, apply a starter high phosphorus fertilizer. Follow the guide of the manufacturer to confirm the amount of fertilizer. Typically, 3.8 pounds of fertilizer is required for 1000 square feet of lawn.

Step 3: Sowing Of New Grass Seeds

Seeds Spreading: Finally, it’s time to spread the seeds. You can spread seeds by hand if there are only one or two bare spots. For the whole lawn, it’s better to use a rotary spreader. Typically, the spreading of 2 to 4 pounds of seeds per1000 square feet is enough.

Watering: After the seeds are sown, you have to keep the ground moist. Watering for at least two to three times is necessary for the next 10 to 14 days. When you see the sprouts emerging, water for at least once a day. The watering schedule should be early in the morning, during windy days avoid using sprinklers as the wind can dry the moisture.

Step 4: Maintenance Of Newly Sown Seeds

  • Save the overseeded area from foot traffic until the new grass reaches the height of the existing one.
  • Keep the soil moist but avoid overwatering.
  • Make sure that your lawn has proper drainage in case of rainfall.
  • Once the grass seeds sprout, avoid any activity on your lawn.
  • You can mow the grass when it reaches the height of existing grass.
  • You can apply weed killer when you have mowed the new grass at least four times.
how to plant a new lawn over an old lawn

How To Plant Grass Seeds on the Existing Lawn in Spring

Well, are you planning to overseed your lawn in spring? If yes, follow are tips mentioned below.

  • Select the grass better suited to your garden and mating climate.
  • For spring, warm-season grasses like Bermuda, and Bahia grasses can be overseeded from March through September.
  • Simply prepare your existing lawn by watering mowing, bagging the clippings.
  • Dethatch the soil and properly aerate the lawn following our above-mentioned guidelines.
  • Fertilize the lawn using a phosphorus-rich fertilizer.
  • Spread the seeds using a spreader.
  • Water the seeds more often until the newly germinated seeds become 1 inch in height.
  • Make sure not to mow and apply pesticides after germination.
  • Once the grass has reached the height of existing plants, mow the garden as required. 

How to Plant Grass Seeds On The Existing Lawn In The Fall

Are you concerned about planting grass seeds on the existing lawn in the fall? If yes, you should not worry. Its procedure is similar to that of overseeding in spring with the only difference of sowing seeds in the aeration holes. You should select the climate favorable grass just like cool-season grasses are bluegrasses, fine and tall fescues, and ryegrasses.

 Shortly, overseeding of the cool-season grass needs aeration of the whole lawn. After this, fall the seeds in the aeration holes. You can also use the back of a rack to put more seeds in the holes. It is a pro tip to prevent the seed from drying out in the cool weather. As a result, the seeds will germinate quickly.

Apply the fall fertilizer and water the seeds one to two times a day. Normally, the seeds require 2 weeks to germinate. Once the new grass reaches the height of the existing grass, you can use a mower to manicure the lawn.

Can You Just Sprinkle Grass Seeds On the Lawn

Most lazy people ask this question: can we just sprinkle the grass seeds on the lawn? The answer is yes, you can sprinkle grass seeds on the existing lawn. But if you do efforts in land preparation before sprinkling new seeds, the end result will be amazing.

 On the other hand, if there are any patches of clear land in your lawn, the distribution of grass seeds is ok. But some of the seeds will not germinate and go waste. You may not get a lush green lawn as a result of throwing seeds over the existing grass.

So, don’t be lazy dude, a super green grass bed is waiting for you, just burn a small number of calories and do some effort in preparing the lawn. It will not only save bucks, the end result will make you happy.

Can You Put Grass Seeds On the Top of Old Grass

Let’s figure this out, can you put grass seeds on the top of the old grass? The brief answer is yes, you can. It is known as overseeding and it is done when your lawn is facing problems of thinning and bare spots. Moreover, overseeding is also done to replace the spring and fall grasses so that seeds may germinate before dormancy in extreme cold. But it needs proper mowing, fertilization, aeration, watering, and sowing of seeds.

If you will just put the grass seeds on the top of old grass, the chances are that the seeds may fail to germinate. The end results won’t be too good. So, if you are investing money, it’s best to invest some of your time and effort to get a healthy and well-maintained lawn.

Related Articles: How to Make St. Augustine Grass Spread Quickly

Final Words

Finally, here is the end of how to plant grass seeds on the existing lawn.

The conclusion is, you can easily plant grass seeds on an existing lawn. You just need to prepare the land to ensure proper oxygen and nutrient supply to the roots.

 Preparing a lawn is simple, just cut the existing grass to 2 inches height. After dethatching, fertilizing, and aerating, put grass seeds better suited to your lawn. Make sure to keep the seeds moist until and after germination. 

If you find this article helpful, make sure to share it with other garden owners.

Lisa Marshall

Hi, This is Lisa Marshall. Lisa has been working with farmers for over thirteen years. It is his passion, hobby and profession. To facilitate other gardeners from her experience, she has decided to start this website to share her gardening experience with her plant lovers.

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