How Soon Should I Cut My Grass?

Are you researching when to mow your new lawn? The answer is a simple maxim: mow as soon as there is something to mow. Get your mower going sooner than expected. We’ll explain why.

New Sod

Question: I laid my rolls only last week. It’s at the height that I should mow it, but it hasn’t filled in the seams yet and it’s not rooted in. I’m afraid I’ll mess it up somehow.

Mow as soon as there is something to mow.

New sod can be walked on, no problem. It’s tough. Don’t get out your football cleats and have a game, but you can walk across it to get places and you should definitely start mowing so the height doesn’t get away from you.

We have another rule of thumb, “Don’t mow off more than 1/3 of a grass blade at a time.” If you want a 1.5” lawn, start mowing it when it’s 2” tall even if it’s not “tacked down” (another way of saying “rooted in”).

Look up the mowing height for your lawn.

Weeds in New Sod

Question: I didn’t butt the edges tightly and now there are weeds growing between the cracks. How do I get rid of them?

Mow as soon as there is something to mow.

Weeds love those cracks (the seams) and they get big fast. Mow those weeds! It stunts them and some even die. It definitely breaks the life cycle and reduces weeds in the future because they never get the chance to go to seed.

New sod with weeds growing in the seams. This sod is rooted in, but the seams haven't filled in yet and weeds had time to take hold. When laying sod, tightly butt edges together to reduce this problem. When soil is disturbed to lay sod, weed seeds are brought to light and they germinate. Go ahead and mow weeds like this to nip them in the bud. Photo from a customer.

Don’t Wait Two Months

Question: I read that I’m supposed to wait two months to cut my new sod, right?

Noooo, get out there and mow as soon as there is something to mow.

“Wait two months” is one of the more detrimental lawn myths out there. Again, it’s about mow height and not mowing off more than 1/3 of a blade per mowing session. If you were to wait two months in the summer to mow Bermuda (even with brand new sod), it could look like a savannah grassland at that point and you’d have to slowly reduce the height over many weeks, otherwise you'll scalp it. 

We've written an article on How to Tame Tall Grass.

At 6-7 inches tall, this Bermudagrass lawn is way too tall. It should have been mowed 3-4 inches ago! They are going to have to follow our steps to tame this tall grass, linked to above. Photo by Stephen Raiford, turfgrass expert at Super-Sod of Charlotte.

This picture portrays double trouble: too tall grass and weeds in the cracks. Mow as soon as there is something to mow, to suppress weeds and so you don't have to tame your tall grass. Photo from a customer.

When not to Mow New Sod

Question: It's time for me to mow my new sod, but it's been raining a lot. The ground is so soft. I have a riding lawn mower - something doesn't seem right about mowing right now. What do you suggest?

Kudos to you for observing the situation and applying common sense! Wait until the ground firms up. If the ground is soft from over watering or rain, hold off mowing, especially with heavy mowers.

When the ground is soft, squishy, soggy, or has puddles, hold off mowing. Otherwise you may get your mower stuck or you may damage your new sod by causing ruts or displacing sod that isn't yet tacked down by the roots. Watch the moisture level and mow when the ground is firm and strong enough to support a mower.  Moist is often fine; soggy is no good.

If the ground is taking a long time drying out and you really need to mow it, consider getting a lighter mower, such as a push mower for a temporary solution or, for a more permanent solution, making the switch to light-weight robotic lawn mowers.

If there is standing water (puddles), you may want to consider fixing that situation by diverting the water away from that area, raising that area with topsoil mixed with Soil3 compost, or by planting trees and shrubs that love water-logged soils. Lawns don't grow well in puddles, so please look into these other solutions.

Grass Seedlings

Question: I planted my Zenith Zoysia or TifBlair Centipede seeds and watered for 2-3 weeks until they germinated (same applies to Elite Tall Fescue seeds, but they germinate quicker). That took a while, now they suddenly seem tall and maybe they need mowing? I’m afraid to hurt them.

Mow as soon as there is something to mow.

Young grass seedlings are tough little guys. They can handle you making a pass over them with your lawn mower. Be sensible and don’t let the kids kick around a ball or play in the sprinkler, but you can get out there and walk across it to mow it.

We recommend mowing soon because this will get you set up for a proper mowing height for your grass. It’s very important not to cut off too much of the tops at once – mow as soon as there is something to mow so you don’t shock it by mowing off too much at once.

This is my neighbor's TifBlair Centipede lawn after 2 months and 1 mowing (timing will be variable depending on conditions). I stopped by and pointed out "there is something to mow." A little hand weeding coupled with the mowing kept the weeds at bay. Photo by Hillary Thompson.

Weeds in Seedlings

Question: There are weeds as tall as my young grass seedlings! What should I do?

Mow as soon as there is something to mow.

Mowing seedlings at a young stage will also keep the inevitable weed seeds in check. Your new grass seedlings need light to grow; weeds can shade them out. You can’t spray herbicide yet, but you can mow to keep weeds from crowding and shading out your seedlings. Plus, you’re keeping weeds from going to seed and creating more weeds.

These seedlings aren't yet tall enough to need mowing. See how they have multiple leaves per little clump? That means they're technically strong enough to withstand a mower, so that if you had a lot of larger weeds you could mow. With just a few taller random weeds like you see here, we recommend hand pulling them. Photo from a customer.

When not to Mow New Seedlings

Question: An area of my new seedling are squishy from run off. I've mowed the rest of the lawn, but am afraid I'll hurt the seedlings or get the mower stuck in this wet area. What do you advise?

Good thinking. Hold off mowing new seedlings until the ground is firm enough to support the weight of the mower.

We have the same caveats here as we do about mowing new sod above, so we've linked you back to that section on when not to mow.

Pro Tip

Conclusion

What’s your conclusion? I hope it’s that you’ll mow as soon as there is something to mow!