Sod is by far the fastest way to turn any empty patch of soil into a lush lawn. If you hire professionals to handle the installation, it’s also the easiest. But there are still some things you should know about maintaining sod during its vulnerable first weeks — for example, how and when to mow new sod and how best to cut it without damaging it.
Fresh sod will need mowing much sooner than grass started from seed. In fact, healthy sod can be long enough for cutting within just two weeks. With the information I’ve covered below, you’ll have all of the necessary knowledge to prevent common mistakes many people make when mowing sod for the first time.
- When Can You Mow New Sod Turf
- Why Can’t You Mow Newly Installed Sod
- How To Mow A New Sod Grass Lawn
- Mowing New Sod Is Different To Cutting Established Lawn
- FAQs When To Mow New Sod
When Can You Mow New Sod Turf
A surprisingly simple rule of thumb is that sod can be mowed whenever the grass is long enough to need cutting. As long as there are no hiccups after installation, most new sod can be mowed within two weeks.
While grass height is a wonderful indicator of when it’s safe to mow, what really matters is whether your sod has taken root or not. This is very easy to test yourself — no fancy equipment or horticulture experience is required. Once you confirm that your new sod has taken root, you can also be confident that the grass will hold up to routine mowing.
Waiting For Sod To Take Root
When sod is delivered, it already contains a network of roots. However, it takes time for those roots to extend past the original layer of sod and into your lawn’s native soil.
Ideally, new sod will produce roots within two weeks after installation. In some cases, however, it can take up to six weeks.
Allowing sod to take root is extremely important for long-term health. If you attempt to mow or permit heavy foot traffic on the sod before it has taken root, the grass may be damaged. You might even find that your new sod lifts from the soil as you mow since there aren’t enough roots in place to hold it down.
How To Test Your Sod Has Rooted
Fortunately, it’s very easy to check whether or not sod has taken root. The University of Minnesota calls this procedure a “tug test.”
Leave the sod alone for at least a week or two so it has a chance to form new roots before checking. Once your sod appears ready to mow, test its root development by attempting to lift a section of sod from the soil. If it lifts with little or no resistance, the sod needs more time to become established. If the sod can’t be easily lifted, it has successfully taken root and can be mowed.
I recommend testing several sections of sod throughout the area. It’s very possible for one section of sod to take root faster than the others. If you find this to be the case, don’t worry! It just means you need to wait longer to mow for the first time.
Grass Top Growth Length
The other big qualifier for mowing new sod is the height of the grass itself. Luckily, this usually goes hand-in-hand with good root development.
I recommend letting your grass grow to at least 3 inches tall before mowing. Don’t let it get much taller, because you want to remove a very small amount of the blades the first time you mow.
Why Can’t You Mow Newly Installed Sod
We tend to take for granted how resilient turf grass truly is. After all, what other plant could you cut on a near-weekly schedule without doing serious damage? While established grass is quite tough, the same can’t be said for brand-new sod. It takes time for grass to develop a strong root system (the secret behind grass being able to survive freezing temperatures, extreme heat, and frequent mowings).
The most common issue with mowing sod too early is that it isn’t yet anchored to the soil. Pushing or driving a lawn mower over the grass can lift or dislodge the layer of sod that was just installed. This can create holes and divots in the lawn surface, as well as damage any roots that have already developed.
When you mow grass, you leave behind open wounds on the blades. Young grass is more susceptible to fungal and bacterial infections that can enter through these cuts. So mowing sod before it is strong enough to fight off disease is a very bad idea.
Those open wounds also release moisture and make the grass more vulnerable to heat and drought. Ensuring new sod gets enough water is hard enough without introducing this extra factor.
One of the great things about sod is that it doesn’t need mowing right away. By the time your new sod is tall enough to mow, it should be well on its way to taking root within the native soil. In other words, there’s no benefit to mowing sod before it’s ready in the first place.
If you mow when the grass is still short, you put the lawn at risk of scalping. Scalping occurs when mower blades are set too low and cut the stems of the grass rather than just the blades. While mature grass can withstand mild scalping, new sod is unlikely to bounce back so easily.
How To Mow A New Sod Grass Lawn
You should let the grass grow just tall enough to be mowed at the highest setting. Cutting any more height while the sod is young will put undue stress on the grass as it is growing. Even though the resultant clippings will be few, I recommend bagging all mowing debris until your sod is well-established.
While sod needs consistent moisture when it is first installed, water should be withheld prior to mowing. This is because the firmer ground will support the mower’s weight better than a soggy surface.
The rules for properly mowing fresh sod are really no different than any other grass. However, the consequences of cutting corners will be far greater than they would be with an established lawn. To prevent damaging your lawn, it’s very important that you follow these tips and any other guidelines provided by your sod installers (if applicable).
Mower Cutting Height For New Sod
I recommend mowing fresh sod with a blade height of 3 inches. With most lawn mower models, this will mean setting the blade to the highest possible setting. Different turf grass species have varying height recommendations.
After you’ve mowed the sod at least three times, you can gradually lower the blade height until you reach the recommended height for your grass type. According to the University of Illinois, you should never remove more than one-third of the grass’ height during a single mowing session.
Water Sod 24hrs Before Mowing
If you have any previous experience with sod installation, you know that watering sod with a sprinkler daily is a must for the first several weeks. However, it’s equally important to withhold water immediately before mowing your new sod.
The last watering session should occur at least 24 hours ahead of your planned mowing time. I recommend withholding water as early as 48 hours before you plan to mow, especially if the soil is already quite soft.
Withholding water before you mow is crucial because you don’t want the soil to be too soft. Pushing a mower over damp sod may tear up the grass. It could also leave behind tire tracks and footprints in the sod. (Plus, you shouldn’t mow wet grass in the first place especially if you have an electric lawnmower. In addition, wet grass can clog up and dull your mower blades.)
By the way, all of this advice also applies to Mother Nature! Keep an eye on the forecast and delay mowing as needed if you get rain the day before you plan to cut your new sod.
Best Time Of Day to Mow New Sod
There are differing schools of thought regarding the best time to mow grass for optimal health. My views are the same as most other leading lawn experts, in that you should mow either in the mid-morning or mid-afternoon.
The reason these two times of day win out is that they are when the grass is least likely to be damp. They’re also when the sun is at its weakest — unless, that is, you feel like mowing in the pitch dark!
As far as specific times go, I like to recommend mowing at either 10 AM or between 2 PM and 4 PM.
By 10 in the morning, any dew from the night before should be dry. Meanwhile, there should still be several hours before the day’s peak temperature.
In the afternoon, all morning dew will be long gone. The concern, however, is that grass needs a bit of time to recover from being cut before the next night’s dewfall. Evening temperatures can also stress freshly cut grass if they drop too low.
If you know rain is in the forecast for the day, it’s a good idea to get the mower up and running sooner rather than later. While you should always avoid mowing when the grass is wet, no harm will come from mowing immediately before rain is scheduled to fall. However, I do recommend keeping an eye on the sky so your mowing session isn’t cut short!
Mowing New Sod Is Different To Cutting Established Lawn
The differences between mowing new sod versus established grass are fewer and farther between than you might think. Nearly all of the advice I’ve recommended here can also be applied to grass grown from seed and lawns that have been in place for several years.
The blade height you use for that very first cut of new grass probably won’t be the height you maintain it at. While some types of grass — such as St. Augustine and tall fescue — prefer to be kept around 3 inches tall during the summer, others thrive when cut much shorter. If your sod features something like a centipede or Bermuda grass, you’ll need to slowly lower the mowing height as the sod establishes itself.
Because of the sheer weight, I don’t recommend mowing new sod with a riding lawn mower. A simple walk-behind mower is much less likely to damage the grass or leave tracks behind in the soil.
Take note of how your new sod is installed before mowing. Most sod is laid down in long strips. Early on, you should push your lawn mower along the seams rather than across them. This will lower the chance of disturbing or pulling up the sod as you mow. Once the grass is well-established, you can alternate your mowing pattern without worry.