Whether you choose seed or sod, cutting too soon will reduce your chances of achieving a beautiful lawn. For a seeded lawn, it takes 4 to 8 weeks to reach the proper height for your first mow, typically 3 to 4 inches. Sod, on the other hand, needs only 2 to 4 weeks before it’s ready.
Always make sure your newly planted seeded or sodded lawn has grown long enough, looks upright, has strong roots, and doesn’t pull up easily when gently tugged. Mowing too early can damage the blades or pull up the roots. Waiting too long can cause the grass to grow too tall, making it more difficult to cut without stressing your lawn.
My guide will walk you through the right time to mow seeded and sodded lawns and how to check if your grass is ready. If you need help with mowing, LawnLove can connect you with a local lawn care pro to take care of your lawn.
When to cut a newly seeded lawn
Mowing too early is one of the most common mistakes people make after seeding a new lawn. Depending on your grass type, local weather conditions, and soil conditions, your lawn may be ready for its first mowing 4 to 8 weeks after seeding or once it reaches 3 to 4 inches in height.
“Begin to mow the new turf when it reaches a height one-third higher than the normal mowing height (e.g., if a 3-inch height is desired, mow when the turf reaches 4 inches),” says Debra Ricigliano, horticulturist at the University of Maryland Extension. This guidance applies to the first mowing after seeding.
For grasses with shorter cutting heights listed on the chart below, such as bentgrass, Zoysiagrass, and Bermudagrass, allow them to grow 3 to 4 inches before your first mow. Then, Ricigliano recommends following the one-third rule for each subsequent mowing until you reach the optimal height for your type of grass.
The chart below outlines the height requirements for when to cut your newly seeded lawn and how to maintain it.
| Grass type | Step 1: Grass should grow to this height for your first mow (inches) | Step 2: Then, cut to this height for your first mow (inches) | Step 3: Regularly mow when grass reaches this height (inches) | Step 4: And regularly cut to this height (inches) |
| Cool-season grasses | ||||
| Tall fescue | 4 to 9 | 3 to 6 | 3 to 6 | 2 to 4 |
| Kentucky bluegrass | 4 to 6 | 3 to 4.5 | 3 to 4.5 | 2 to 3 |
| Fine fescue | 3 to 6 | 2.25 to 4.5 | 2.25 to 4.5 | 1.5 to 3 |
| Perennial ryegrass | 3 to 6 | 2.25 to 4.5 | 2.25 to 4.5 | 1.5 to 3 |
| Bentgrass | 3 to 4 | 2 to 2.67 | .38 to 1.5 | 0.25 to 1 |
| Warm-season grasses | ||||
| Bahiagrass | 6.75 to 9 | 4.5 to 6 | 4.5 to 6 | 3 to 4 |
| St. Augustine | 5.6 to 9 | 3.75 to 6 | 3.75 to 6 | 2.5 to 4 |
| Buffalograss | 4 to 9 | 3 to 6 | 3 to 6 | 2 to 4 |
| Centipedegrass | 3 to 4 | 2 to 2.67 | 2.25 to 3 | 1.5 to 2 |
| Zoysiagrass | 3 to 4 | 2 to 2.67 | 1.5 to 3.75 | 1 to 2.5 |
| Carpetgrass | 3 to 4 | 2 to 2.67 | 1.5 to 3 | 1 to 2 |
| Bermudagrass | 3 to 4 | 2 to 2.67 | 1.5 to 3 | 1 to 2 |
Read more:
How to Cut Long Grass
How to Mow a Lawn the Right Way
How to know your newly seeded lawn is ready to mow
Height: While it’s good to go by the calendar, grass height is the best indicator of when to mow. Generally, most grasses must reach at least 3 to 4 inches before mowing. This makes them tall enough to be strong, develop deeper roots, and better handle the stress of mowing.
You may have noticed that some grasses in the chart above have a higher range — between 6 and 8 inches — for the first mow. I suggest cutting your new grass at no higher than 5 inches to avoid stressing your new lawn.
And remember, never cut more than one-third of your grass at one time.
Uniformity: Your new lawn should appear even, dense, and upright before you mow. Your grass blades should stand tall and show signs of healthy growth, not be thin, floppy, or sparse. A patchy or weak-looking lawn signals that the grass needs more time to mature.
Blade development: Your seedlings should have more than a single sprout. Look for signs that each plant has produced several blades of grass. This indicates that your grass is maturing and has begun to develop a fuller structure, which helps it withstand mowing and foot traffic.
Root strength: Before mowing, your new grass must be firmly rooted in the soil. Mowing puts pressure on grass blades and their roots. If the roots aren’t strong enough, the mower can pull your new grass out of the ground.
Read more:
When to cut a newly sodded lawn
Establishing a new lawn with sod offers the advantage of an instantly green landscape, but you need to allow the sod adequate time to develop strong roots before the first mow. “Sod may be ready to be mowed within 2 to 3 weeks of planting,” says turfgrass experts at the University of California’s Integrated Pest Management Program.
How to know your newly sodded lawn is ready to mow
Growth: An easy indicator that your sod is ready to mow is visible, healthy growth. Although the grass blades are already mature when you lay sod, you want to see them continue growing in their new environment, this shows that the roots are starting to function and the sod is adjusting well to your soil.
If your grass has grown about 1 inch taller than it was at the time of installation, it means it is growing and is ready to be mowed. If your sod looks the same as it did when it was installed, that means it has not rooted yet or is under stress, like compacted soil or lack of sunlight.
Root check: Even when sod looks like a finished lawn, it’s only surface-deep at first. Root development begins around 7 to 10 days after installation, but can take up to 3 weeks. Mowing too soon could cause the sod to shift, wrinkle, or tear.
To check whether your sod has rooted, gently try to lift a corner or edge of a sod trip. If it lifts easily, it’s not ready. If it resists pulling and feels firmly anchored, that’s a sign roots have begun to establish.
Soil check: Sod already has mature grass but it still needs time for its roots to take hold. A good way to check this is to pay attention to how the ground feels under your feet. If it feels soft, squishy, or unstable, like shifting under your weight, the soil underneath hasn’t firmed up yet and isn’t ready for mowing.
Read more:
The Best Types of Sod for an Instantly Lush Lawn
Grass Seed vs. Sod: What’s Best for Your Lawn?
How Much Does Sod Cost to Install?
How to Get Rid of Sod Webworms in Your Lawn
FAQ about cutting new grass
Uneven grass growth can occur for several reasons, such as the grass seed being spread unevenly or some areas receiving more sunlight, water, or nutrients than others. If the seed is old or of poor quality, it may germinate patchily.
With sod, uneven growth could be due to air pockets under the turf, uneven soil grading, or poor root contact with the soil in some areas. In both cases, you need patience, uneven growth evens with time, regular mowing, and consistent care. If not, you can overseed sparse spots.
If you wait too long to mow, the grass can get too tall and start to bend or mat down, which makes it weaker and harder to cut cleanly. Tall grass can also clog your mower, causing it to work harder and resulting in uneven cuts or clumps.
Yes, but it’s best to use a lightweight push mower at first. Avoid heavy riding mowers until your grass is well-rooted and the soil is firm. Whatever you use, make sure the blades are sharp, and only mow when the grass is dry.
Get your new lawn off to a great start
New grass needs a careful start. Mowing too early or too aggressively can ruin all of your hard work. Lawn Love can connect you with experienced lawn care pros in your area who know the right timing and techniques to help your lawn grow strong and healthy.
Sources:
“Care and Maintenance of a Lawn after Seeding.” By Debra Ricigliano, Maryland Certified Professional Horticulturist, University of Maryland Extension.
“Mowing new lawns.” University of California’s Integrated Pest Management Program
Main Photo Credit: encierro | Adobe Stock Free | License
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