After overseeding, it’s essential to wait at least 4 weeks before you mow your new lawn. To be sure your new grass can handle the stress of mowing, wait until it grows to a height of 3.5 inches (9 cm). Then, take hold of a few grass blades and tug. If the new grass resists being uprooted, it can withstand mowing. As long as you’ve followed a new grass watering schedule and weather conditions are dry enough for safe mowing, you can then mow your newly overseeded lawn.
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What Happens if You Mow Too Soon After Overseeding?
Mowing too soon after overseeding can destroy your new grass seedlings. The pressure of mower wheels and footsteps on new grass can kill the seedlings. Plus, the suction from the lawnmower blade can uproot grass sprouts that are too young to be mowed.
- If the grass is too young to be mowed, the weight of mower wheels can crush and kill the grass blades.
- Spinning mower blades create suction that can uproot grass that is too young for mowing.
- Cutting large portions off young grass can damage or kill the new grass plants.
Mowing a recently overseeded lawn can also cause serious damage to the grass blades, which can kill the new grass plants. When mowing new grass, it’s essential to cut off only a small portion of the grass blade to start. Then, as the grass becomes established, you can gradually lower your mower blade until you are mowing your lawn at the desired height.
5 Signs Your lawn is Ready to Be Mowed After Overseeding
No matter whether you are growing warm-season grasses or cool-season grasses, it’s essential to wait for your newly overseeded lawn to establish itself before mowing. If your lawn is looking shaggy after overseeding, here’s how you can tell if your grass is ready to be mowed.
Time Will Tell
Grass seed requires time to establish strong roots and blades before it can survive mowing. For most species of grass, 4 weeks is the ideal time to wait between overseeding and firing up your lawn mower for the first time. If 1 month has passed since you’re overseeding, you can begin testing your lawn to see if it’s ready to be mowed.
- Allow at least 4 weeks between seeding and mowing an overseeded lawn.
- Some grasses take weeks to begin sprouting after you spread them, so you may have to wait 6–8 weeks before you mow.
- 4 weeks after overseeding, begin testing your new grass using the other tips on this list.
Keep in mind that how soon your grass is ready to be mowed depends on the type of grass you are growing. Many grass varieties begin germinating a few days after you overseed your lawn. Meanwhile, Kentucky Bluegrass, Buffalo Grass, and Bermuda Grass can take up to 30 days to germinate. If you’re overseeding your lawn with one of these grass types, you may have to wait 6–8 weeks before you mow your overseeded lawn.
Check the Height
Don’t mow your overseeded lawn until the new grass is at least 3.5 inches tall (9 cm). If the grass is shorter than this, mowing can cause significant stress to your new grass blades. This stress can kill off large quantities of newly sprouted grass, destroying your overseeding efforts.
- Measure the height of your new grass to determine if it’s ready to be mowed.
- Wait until the grass is 3.5 inches tall (9 cm) before mowing for the first time.
- Mow new grass at a blade height of 3 inches (7.5 cm) to prevent damaging your grass seedlings.
When you mow new grass, set your mower blade very high. When mowing new grass that is 3.5 inches tall (9cm), set the blade to 3 inches (7.5 cm). By cutting off only a small portion of the blade the first time you mow new grass, you limit damage and allow the young grass to bounce back.
Do a Pull Test
To make sure young grass can withstand being mowed, perform a pull test. Find a few clumps of young grass sprouts in your yard, grab them near the base, and give them a firm tug. If the grass resists being uprooted, it can hold up to mowing. If the grass uproots easily, then it’s not ready to be mowed.
- Do a pull test by grabbing new grass at the base of the blades and tugging firmly.
- New grass that resists being pulled out of the ground is strong enough to survive mowing.
- Grass that uproots easily isn’t ready for mowing.
- Test several areas of your lawn to make sure all your overseeded grass is ready to be cut.
It’s best to perform this pull test in several areas of your lawn. Overseeded grass may grow quickly in sunny areas, while shady parts of your lawn may take root more slowly. Make sure the new grass is firmly rooted throughout your entire lawn before you start mowing.
You’ve Followed a Strict Watering Schedule
Another sign that your overseeded lawn is ready to be mowed is if you have followed a watering schedule that promotes fast growth. Our guide to watering grass seed will help your seeds germinate faster and develop strong roots quickly. If you have watered your grass two times per day until the seeds begin to sprout, your lawn is far more likely to be ready for mowing 4 weeks after overseeding.
- Water your overseeded lawn twice daily to promote grass seed germination and faster grass growth.
- Keep the soil in your lawn moist to allow new grass to develop roots that help it survive mowing.
- If you water your new grass less frequently, it will take longer before it’s ready to be mowed.
An overseeded lawn needs to have consistently moist soil. This environment encourages grass seeds to germinate at a high rate and allows baby grass to grow strong roots quickly. As your grass grows taller, you can gradually taper off until you are watering your lawn twice weekly. However, frequent watering is key to getting your overseeded lawn ready for mowing as fast as possible.
Weather Conditions are Right
Pick a dry day to mow your overseeded lawn for the first time. You should never mow grass when it is wet. Mowing wet grass can tear and destroy your lawn. If you are mowing an overseeded lawn, wet conditions can kill off your baby grass.
- Do not mow an overseeded lawn if it is wet from rain or dew.
- Mowing in wet conditions can destroy young grass.
- Mow in the mid-morning or late afternoon to put the least amount of stress on your lawn.
Remember to avoid mowing too early in the day. Grass that is still damp with morning dew will be torn up by your mower blade. Instead, mow in the mid-morning when the grass has dried. Otherwise, wait until late afternoon to mow. This will put less stress on your grass and make for an easy mowing job.
How Often Should You Mow After Overseeding?
Once your overseeded lawn is ready to be mowed, you can begin following a regular mowing schedule. This means that mowing your overseeded lawn once per week is perfectly fine. Although it’s best to start mowing your overseeded lawn at a mowing height of 3 inches (7.5 cm), you can gradually lower the blade if you want a shorter lawn. Each week, lower the blade one-quarter of an inch (6 mm) until you are cutting your grass at the desired height.
Should You Bag Your Grass Clippings After Overseeding?
There is no need to bag grass clippings when mowing an overseeded lawn unless portions of your lawn are diseased. Grass clippings decompose surprisingly fast. They also return nutrients to the soil as they break down, which gives your newly seeded lawn a growth boost. If portions of your lawn are afflicted with rust or fungus, it’s best to bag and trash grass clippings to avoid spreading the disease. However, there’s no reason to bag grass clippings when mowing a healthy, green lawn.
How Soon Can You Mow After Overseeding?
The exact timeline between overseeding and mowing your new lawn depends on the grass type you are growing. The good news is, no matter what type of lawn you have, there are some easy ways to tell if your overseeded lawn is ready for the mower:
- Wait at least 4 weeks before testing your lawn—new grass needs at least this long to become established.
- Measure your new grass sprouts—if they’re 3.5 inches (9 cm) or taller, they’re probably ready to be mowed.
- Grab a clump of new grass and pull—if its roots hold strong, the grass can withstand mowing.
- If you’ve watered your new overseeded lawn frequently to promote seed germination, your grass will be ready to mow sooner.
- Make sure your lawn is dry before you mow.
These simple tips will ensure you mow your lawn at the perfect time. This way, you’ll encourage a lush lawn and won’t harm any of the new grass you worked so hard to cultivate.