What's The Best Time to Mow New Grass?

Ben Kissam
Written by Ben Kissam
Updated May 3, 2022
A man mowing the lawn
Photo: dmphoto / E+ / Getty Images

Highlights

  • You should wait four to six weeks to mow newly seeded grass.

  • The exact time depends on the type of grass, amount of sun exposure, irrigation, and more. 

  • Mowing new grass is very important for its health and strength.

  • Use sharp blades and a mower bag to prevent uneven cuts when you mow.

  • Water new grass after you've finished if it's particularly hot or dry where you live.

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Growing new grass on your own can be a challenge—even if it's a great way to save money on lawn care. You're certainly not the first person that's seeded a new area of their lawn who’s now stuck with a few follow-up questions. For example, when should you mow new grass? 

The answer, while pretty straightforward, does vary depending on a few factors. For example, if you mow too soon, you could take your grass up by the roots and negate all that hard work. Learn the best time to mow new grass in this short informational guide.

When Is the Best Time to Mow New Grass?

Four to eight weeks after seeding new grass is the right time to go over it with a mower. Of course, the number of days or weeks will fluctuate based on your climate, how much water your grass gets, and the amount of sunlight it receives. 

In colder, shadier climates, you may need to wait six to ten weeks. For the most part, this applies to all types of grass. But if you know what you've planted, research to see if any adjustments are needed or consult a reputable lawn care provider to help formulate a plan for your new grass.

How Long Does It Take for New Grass to Grow?

You could see new grass sprouts after five to 30 days. But exactly how fast your grass will germinate depends on the type of grass, sunlight exposure, age of the seeds, irrigation, and time of year. While cold-season grasses will sprout the fastest, warm-season varieties can take 30 days or more. 

Mowing New Grass Helps Strengthen the Root

A mowing green grass on a sunny spring day
Photo: rostov777 / Adobe Stock

Eventually, yes, but not right away. Mowing newly seeded grass is essential for the health and growth of your new grass—but it might not be ready for the rigors of a powered mower right away.

Mowing your lawn actually helps strengthen the roots of the grass. Similar to when a person works out, the stress imposed on the grass when the mower passes over it and cuts the top of the blades tells the grass to strengthen its roots so a mower can't pull it out.

Mowing your lawn on a regular schedule also helps create a natural fertilizer for your lawn by recycling organic nutrients back into the soil.

How to Mow New Grass for Best Results

Here are five tips to make mowing your newly seeded grass a successful endeavor.

1. Make Sure Your Blades Are Sharp

Dull blades affect your grass's health and look when you mow your lawn. You want freshly sharpened blades to help take the right amount of grass off and ensure your new grass doesn't grow crooked or patchy.

2. Set Your Mower Blades Higher

Most mowers are set at three inches— don’t go any lower than this when you first mow. In fact, you might consider raising the blades a half inch higher to play it safe and encourage deep roots. Each lawn mower is different, so read your user manual or do an online search on how to do this. It should only take a few minutes.

Some types of grass, such as creeping bentgrass, actually thrive when cut as low as one-half an inch.

3. Use a Mower Bag

Attach the mower bag onto your lawn mower to pick up all the grass it cuts, as patches of dead grass could suffocate your newly seeded areas. Dispose of the grass you pick up in bags or a compost pile.

4. Mow New Grass When It's Dry

Wet grass tends to gum up a lawn mower, resulting in a more uneven cut. Give it an afternoon or even a day or two before going over the mower, even if your new grass needs it. 

5. Water the Grass Right After Planting During Dry Seasons

Planting seeds is just the beginning of your project task list. Even once it's taken hold and starts growing, new grass seed still needs good conditions to sprout. If it's been particularly hot or dry where you live, water the new patches of grass immediately after you finish. Help your new grass thrive!

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