Can You Mow Wet Grass? 7 Reasons to Give It a Second Thought

While it can be tempting to mow your lawn whenever you have spare time, it’s worth stopping to consider whether you can mow wet grass. 

From turning your grass brown to spreading fungal disease, learn why you should hold off on mowing your grass until it’s dry. If you must mow your grass when it’s wet, be sure to follow our best practices for mowing damp grass. 

Can You Mow Wet Grass?

Mowing wet grass isn't a good idea—it can damage your grass, your mower, and even yourself. Cutting wet grass can clog your mower, cause fungal disease, and leave behind clumps that kill your lawn. If you have an electric mower, you could even suffer an electric shock. The best grass-cutting technique is to wait until your grass and soil are dry to the touch, usually 2 to 5 hours after a light rain. You may need to wait a full day or more if there was heavy rainfall. 

7 Reasons You Shouldn’t Mow Wet Grass

Mowing wet grass can damage you, your grass, and your mower. Here are the main reasons to avoid mowing your grass when it’s wet. 

Difficulty Mowing and Unattractive Results

Wet grass blades are slick and harder to cut, making mowing more of a chore. And rather than getting a clean cut, you’re more likely to tear the grass blades, too, which can cause the ends to turn brown. 

Mowing when the ground is soft and soggy can tear up the soil and even the roots of your grass, damaging your lawn. Mowers are heavy machines that can leave wheel ruts and divots, compacting the soil and making your lawn look messy and uneven. 

Damage to Your Mower

Your mower will suffer more wear and tear when cutting wet grass. Water from your grass and soil can seep into your mower’s fuel tank and cause the engine to malfunction or stop working. Water can corrode your mower’s parts over time, leading to expensive repairs or replacing your mower altogether.

Wet grass clippings can also clump up and block your vacuum or blade, leading the machine to work harder and overheat. 

Possible Electric Shock

If you have an electric lawn mower, especially one with an extension cord, mowing wet grass poses a risk of electric shock. If any connections, including wiring or damaged cord, come in contact with moisture, it can lead to electrocution—not to mention damage to the mower. 

Physical Injury Due to Slick Grass

Walking on wet grass can cause you to slip and fall, risking injury. It’s especially dangerous if you fall near the mower’s blades or hard landscaping like brick or stone. If it’s raining while you mow, it will reduce your visibility and you will have a harder time seeing where you’re going.

Spread of Disease and Weeds

If your lawn has a fungus, which can happen with excessive rainfall, mowing can spread the disease further. Diseases such as brown patch disease can develop after a rainstorm. 

Wet clumps of grass sitting on the lawn or your mower can also increase the chance that your lawn will get a disease. Wet grass tends to stick to the underside of your mower, causing mold and fungi to grow, spreading it the next time you mow the lawn. If you have lawn weeds going to seed, usually in the spring, mowing wet grass can increase the spread of your weeds.

Stained Shoes and Clothes

While it’s not as serious of a risk as an electric shock, it’s worth noting that cutting your grass while it’s wet could damage your mowing outfit. Mowing wet grass can cause more vibrant grass stains on your socks, clothes, and shoes. It’s better to wait until a dry day for easier clean-up.

More Clean-Up Work

No one likes extra work. But if you mow wet grass, you’re in for a whole heap of extra clean-up work. Damp grass easily and quickly builds up on your lawn mower’s undercarriage, getting into every nook and cranny. This includes the mower blades, which could get clogged up, leading to damage. 

Plus, wet grass gets slung everywhere when you mow it. It will get all over your house, car, and your clothes, staining them all in the process. If you don’t want to have to take a very long time cleaning up the entire underside of your lawn mower, your clothes, and yourself, mowing wet grass should be a no-go for you. 

What to Do if You Must Mow Wet Grass

If you have to mow after a rainfall, the best course of action is hiring a local lawn care service that can navigate the difficult wet-cutting process. If not, there are a few ways to make the job easier and protect your grass. 

Use a Commercial Mower

Commercial mowers cut wet grass better than residential lawn mowers. The blades and discharge system tend to be more robust. They are less likely to tear your grass or leave wet clumps in your lawn. 

Always avoid using an electric mower on wet grass, and keep in mind that a battery-powered mower is more likely to corrode when wet.

Use a Side-Shooter and No Bag

Set your mower to side-discharge without a bag. The grass cuttings will be left in rows for easier manual bagging later. You’ll also save the mess of cleaning a mower bag with a damp interior.

Sharpen the Blades

Sharpen your mower blades if you need to mow a wet lawn to allow for crisper, cleaner cuts. You may need to pass over the lawn more than once to get everything cut, but sharp blades will help make it easier and faster. 

Set Your Mower to the Highest Setting

It’s hard for a mower to get a clean cut at a lower level when the lawn is wet. Set the mower to the highest setting to allow it to cut the blades as crisp as possible. For most grasses, that means a blade height of three or four inches. But some grasses, like Zoysia and Bermuda, should be cut when the blades are 2 inches tall. Check the type of grass and the preferred height before mowing.

Clean Off the Underside of the Mower

Don’t try to unclump your mower blades while the machine is running, as it is a huge safety risk. Always unplug and turn off your mower and disconnect the spark plug before touching a mower blade. 

Once the machine and the spark plug is off, brush off the tires, underside, and blades of the mower. Remove as much of the wet grass as possible, to avoid mold growth and fungi that can later spread to your lawn. Be sure to clean your shoes and clothes right away, as wet grass can leave deeper stains.

Cut Slower

As they say, slow and steady wins the race. You may be able to go full steam ahead when you’re mowing a dry lawn, but if you can’t avoid mowing wet grass, you should keep it at a snail’s pace. Wet blades of grass take more effort for your mower blades to cut effectively, and if you’re going too fast, you’ll end up with a patchy, uneven yard. 

Use a Fuel Stabilizer

Moisture can quickly impact the engine on your lawn mower, decreasing its overall power and performance. Mix some fuel stabilizer in with your regular fuel. This will keep your mower running more efficiently, even if it’s battling wet grass. You can find fuel stabilizer at most home improvement stores and in many places online.