You should not mow after overseeding because this will only end up crushing the new seeds under the lawn mower’s weight. That is why we always recommend that lawn owners mow the grass before overseeding.

Mow After Overseeding

Once overseeding has been carried out, you must be patient for at least four to six weeks.

Find out why mowing after overseeding is not a good idea and when the right time to mow an overseeded lawn is.

Is Mow After Overseeding a Good Idea?

No, mow after overseeding is not a good idea, so postpone mowing the lawn for at least four weeks after overseeding it with new grass seeds. Otherwise, you will end up damaging the new grass and the seeds, ultimately defeating the whole purpose of overseeding. 

Other negative effects of mowing right after overseeding include the newly-planted grass becoming uprooted by the lawn mower, the grass blades being crushed by the machine, and the lawn looking uneven after mowing. Here are the various reasons why you should not mow after overseeding your garden.

– The Seeds Will Not Germinate

Overseeding an existing lawn using new seeds of the grass type that is already growing there is important to fill up the bare spots developing within it. These seeds are only superficially sprinkled over the lawn, giving them ample sunlight amidst grass blades. Mowing the lawn soon after seed sowing will end up crushing these superficially strewn seeds. 

You should not even walk over the lawn in the first one to two weeks because seeds and seedlings are extremely sensitive. The larger and heavier the lawn mower used, the more damage will be incurred to the seeds. In the worst-case scenario, very few seeds will be able to germinate, and your overseeding operation will fail.

– New Grass Blades Will Be Crushed

The new grass blades from the overseeded seeds are very small and sensitive for the first four weeks. Even minor foot traffic from kids and pets can crush them and prevent them from growing. Imagine how much damage will be caused by a riding-type lawn mower that is almost twice as heavy.

Is Mow After Overseeding a Good Idea

When fresh grass blades soon after germination are crushed, this causes irreparable damage. These seeds are too young to repair themselves and regrow. The damaged leaves also become easily susceptible to disease by fungal infections and pests. You will wonder why the bare spots you sought to fill over are still present despite overseeding.

– New Grass Gets Uprooted

A lawn mower blade creates suction while it rotates during functioning. The intended purpose of this section is to lift the blades so they can be cut smoothly and forcefully. In the case of overseeded young grass, this suction will end up pulling it out. 

Once the grass is out of the ground and its roots, you can say goodbye to it forever. After cutting grass within three to four weeks of seeding, you will see uprooted grass strewn all over the lawn. This happens because of inadequate root development, as the shallow roots cannot resist the upwards suction.

– Too Much Grass Gets Cut

Scientifically, cutting off a blade of grass more than one inch of its length will kill it. This means that the longer a grass blade, the more you can cut off. That is why a blade must be three and a half inches long before one-third of it can be cut off safely. 

Cutting soon after overseeding means cutting off major portions of the small young leaves. The leftover grass after mowing will not be able to survive or grow back. It will not even be able to heal its cut parts and will succumb to fungal rot. Your newly planted grass might turn brown before dying in such unfortunate circumstances.


When Is the Right Time To Mow After Overseeding?

The right time to mow after overseeding is after four weeks have passed since the grass was planted. Before taking the mower out, confirm that the new grass blades have uniformly become three and a half inches long throughout the lawn, which means it is strong enough to be mowed. 

So how will you know if the grass is ready to be mowed after overseeding? It is important to give the grass ample time to grow strong and healthy. You should also check the height of the grass and its strength by trying to pull out several handfuls. Here are some other things to do after overseeding and before mowing your lawn.

– Give Grass Time To Grow

Newly sowed grass seeds must be left alone before you can carry out lawn mowing over them. It is important to leave them undisturbed so they can germinate and sprout new roots and shoots. The newly sprouted leaf blades from overseeding need time to grow long and strong enough to survive being cut for the first time.

Most commonly planted grass varieties in the US need approximately four weeks to grow tall enough to be mowed. It is safe to assume that an overseeded lawn can be mowed after one month. However, it would help if you still carried out certain tests to be 100 percent sure of this.

Some grass types take much longer to germinate and then establish themselves. They take several weeks to germinate from seedling to the leaf blade stage. It would help if you waited for these grasses more than regular grass before mowing.

If you have planted slow-growing grass in the lawn, wait six to eight weeks before mowing it. Some of the most popular lawn grasses are included in this category, such as Kentucky bluegrass, Bermuda, and buffalo grass

give the grass ample time to grow

– Check the Height of the Grass Blades

The height of the new grass blades that have sprouted after overseeding indicates whether it’s time to cut the grass or not yet. A good standard is that the grass blades, on average, need to be three and a half inches long before they can be cut. Only then will the grass survive without sustaining serious damage.

Remember that you can only cut one-third of a grass blade during one mowing session. When more than one-third of the blade’s length is cut off, there are very high chances of it dying soon after. Newly sprouted leaf blades are even more sensitive to stresses like this; that is why we need to allow the grass to grow as tall as possible before mowing it down. 

As a precautionary measure, set the height of the mower blades at their highest possible setting. Once you have measured your grass height to three and a half inches, your mower blade needs to be set at three inches. You might not cut the grass down as much as you would like, but this is best for the lawn’s long-term health.

Generally, warm-season grasses like Bahia and Centipede can be cut shorter. This is compared to cool-season grasses, such as perennial ryegrass, which are slightly more sensitive to cutting.

– Try Pulling the Grass Out

After you have measured the grass height of a newly overseeded lawn and it seems adequate, the next step is to pull the grass out to test its root strength. Grab a thick clump of grass strongly in your dominant fist as close to the ground as possible. Give this handful of grass a strong upwards pull and notice the resistance provided by the roots.

The ultimate goal of this test is to determine whether or not the grassroots have grown underground extensively enough to support the blades.

If the grass resists being pulled out, then this means that the roots have grown adequately, and you can safely mow the grass. If the grass gets pulled out of the ground easily without any resistance whatsoever, then this means that its roots need more time to grow.

You can see the roots of the tuft of grass easily uprooted by your own eyes. These will be short, thin, and wispy looking. Try this test in various patches of the lawn to get a general idea of the growth all over it.

The grass may have grown faster in sunny and ventilated patches of the lawn, whereas the root growth in shady areas will be far behind. You should proceed with the mowing only once the pull test is uniform throughout the lawn.

– Follow a Good Watering Regime

One thing that will help cut grass earlier after overseeding is when you have been following a regular and strict watering regime from the start. Starting a regular watering schedule even before overseeding ultimately promotes a faster grass growth rate. Three to four days before overseeding the grass, start watering the lawn superficially every day.

The seeds respond better when planted in soil that is hydrated well for a few days. After sowing these seeds, you need to keep the soil from becoming completely dry, at least in the first few days. Whenever the top two to three inches of soil begin to dry, turn the sprinklers on at a shallow depth for five minutes each time. 

The best time for overseeding any lawn is during the early autumn season, and you will only have to water this soil twice or thrice a day. Overseeding during hot weather has one major disadvantage: seeds must be watered as much as five to six times a day. After following this regime for one week, you can start tapering off until you water only once per week. 

– Check the Weather

Weather conditions greatly influence how soon you can mow after overseeding. Overall, it helps if overseeding is carried out in the early to late fall. The seeds can be watered less, and the grass can be cut once or twice before the winter thaw.

The weather on the day of the lawn mowing also matters a lot. First, the day should be dry and sunny because it is unwise to cut wet grass. Wet grass does not get cut easily and instead ends up tearing. Cutting wet grass damages the lawn mower and forms clumps all over the lawn. 

For recently grown grass blades after overseeding, mowing them in a wet state will cut them. Refrain from mowing the grass that is even slightly moistened from dewdrops early in the morning — wait until mid-afternoon until it dries. The safest time to mow an overseeded lawn is either in the middle of the morning or during late afternoon. 

How Do You Mow the Lawn After Overseeding?

To mow the lawn after overseeding, make sure you have a consistent watering schedule for the first few weeks after overseeding. Wait for the perfect time and day for mowing, and make sure that your mower blades are sharp. Mow the lawn carefully and do not bag the clippings.

Let us learn how to mow a lawn after it has been overseeded using these simple tips and tricks from seasoned professionals. 

– Carry Out Overseeding

Overseeding can be carried out simply by superficially spreading the seeds of the grass over existing grass and on the bare spots. However, to spread seeds evenly, you must do this systematically. Purchase or load a seed spreader, load the seeds on it and use it for overseeding.

The best way is to divide the lawn into vertical and horizontal lines and walk along these lines while holding the spreader. The required seed density varies from lawn to lawn, but around 16 seeds per square inch of the lawn are adequate for most grass types. 

– Create a Consistent Watering Schedule

Newly spread seeds need way more water than you can imagine. The key is to keep the soil dry within its top two inches during the first three days. The recommended best time to overseed is during the autumn season because the soil will stay moist much longer, and you will only have to water it once or twice a day. 

When a lawn is overseeded during summertime, the soil dries much more rapidly and will need up to six or seven daily watering sessions. Still, you do not want to overwater the lawn, so it is important to water superficially for only five minutes per session, especially during summer. 

Before you can get down to mowing a freshly overseeded lawn, you must give it some time. During the next four weeks, regularly watering the lawn deeply but infrequently is a great way to promote a rapid growth spurt. 

Deep watering means turning the sprinklers on for about 15 to 25 minutes during each session and using only a moderate quantity of water. When you water for so long, it saturates the soil well. The deeper the soil is saturated, the deeper the new roots will grow, which is exactly what we want. 

– Wait for the Right Time and Day

Once four to six weeks have passed since seeding, your new grass can finally be cut. The grass growth will be even more spectacular if you consistently follow a strict watering regime for the past four weeks. 

Go through the weather forecast to select a dry, sunny, and bright day for lawn mowing. Put on some sunscreen and wear a hat for sun protection, as mid-day is ideal for mowing. This is when even the dewdrop moisture from the early morning will have evaporated, and the grass blades will be bone dry.

Cutting wet grass is difficult and often gets torn during the process. It also gets stuck in clumps on the mower deck and lawn parts. Take your mower out and make sure it is well-maintained and in good working condition before you mow.

Right Time To Mow After Overseeding

– Sharpen Your Mower Blades

If it has been a lengthy time since you last sharpened your lawn mower blades, now would be a good time to do so. The newly grown grass is too delicate and sensitive and must be cut with the sharpest blade. Do not cut grass using a dull blade because it will be crushed and torn up. 

Sharpening the mower blade is easy; you must first unbolt it from the mower. Then, after having thoroughly cleaned it, you should use an electric angle of 45 degrees to the cutting edge to sharpen the blade.

If an electric angle is not available, then a sharpening stone is also a worthy alternative. Lastly, thoroughly wash the dirt and grit off the blade before reattaching it to the mower.

– Mow Carefully 

Refrain from trying to save time by mowing quickly over the overseeded grass. Instead, being patient and moving slowly across the lawn is wise. Remember that the new grass is still growing and has developing roots, so there are high chances of it being uprooted by the lawn mower. 

Set the mower blade at its highest possible setting and make sure that it rotates at a moderate speed. For new grass, using a small-sized and lightweight lawn mower works better than a gigantic bulky one.

– Do Not Bag Your Clippings

You can bag grass clippings after cutting fresh grass if you like, but it is healthier if you go for a mulching type of blade and instead spread these clippings over the lawn. Even with a regular blade, you can manually convert the cut grass into mulch and spread it evenly on the surface of the lawn.

We all know that grass clippings are rich in nutrients, which is precisely what a young grass needs after its first cut. Mulched clippings are very small and break down easily to become food for the growing grass. 


Before we let you go after reading this comprehensive guide on mowing a lawn that has been overseeded, let us summarize all the important points first.

  • Using a lawn mower over a newly seeded lawn will physically crush each grass seed under its weight.
  • The suction created by a rapidly rotating lawn mower blade also rips the new grass blades along with their shallow roots.
  • Until the new grass blades from overseeding become three and a half inches long, mowing them will cut more than half their lengths off, killing them. 
  • Try pulling the young grass out from a few spots in the lawn using your hand to see if root resistance is present.
  • Always mow new grass on a dry day because cutting wet grass is more difficult. A warm-season grass can be cut shorter than cool-season grass varieties. 

After reading our advice, you will surely never commit the mistake of mowing grass within a month of overseeding. This is the best way to get successful results from overseeding and to enjoy a lush lawn as the fruits of your labor. 

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