Can You Mow Wet Grass?

The British weather rarely cooperates with our mowing schedules. With frequent rain, morning dew, and unpredictable showers, waiting for perfectly dry grass isn’t always practical. But can you actually mow wet grass, and should you?

The Short Answer

Yes, you can mow wet grass, but you probably shouldn’t unless you have to. Cutting dry grass produces better results with less effort and causes less damage to both your lawn and your mower.

Sometimes you have no choice. If the grass is getting too long and dry weather isn’t forecast, mowing wet may be the lesser evil. But understanding the problems helps you minimise damage when wet mowing is unavoidable.

Problems With Mowing Wet Grass

Wet grass creates several issues that don’t occur when cutting dry.

The most obvious problem is clumping. Wet clippings stick together and to your mower deck, forming heavy clumps that drop on the lawn and smother grass beneath them. Instead of a clean cut, you get scattered lumps of soggy grass.

Wet grass doesn’t cut cleanly. The blades bend away from the mower rather than standing upright for a clean cut. This results in torn, ragged edges rather than a neat trim. Torn grass turns brown at the tips and is more susceptible to disease.

The cut is uneven. Some grass bends flat while other blades get cut, leaving a patchy, inconsistent finish that looks worse than not mowing at all.

Damage to Your Lawn

Beyond the poor cutting quality, mowing wet grass can physically damage your lawn.

Wet soil is soft and easily compacted. Mower wheels pressing into soggy ground compress the soil, reducing air and water penetration to roots. Repeated compaction in the same wheel tracks creates permanent damage.

Wheel ruts form in very wet conditions. These visible tracks don’t recover quickly and create an uneven surface that’s harder to mow properly in future.

Wet conditions favour disease spread. Fungal spores transfer more easily on wet grass, and the wounds from ragged cutting provide entry points for infection. Mowing when wet can spread problems like red thread or fusarium across your lawn. See our guide to lawn diseases for more on this.

Damage to Your Mower

Your mower doesn’t enjoy wet grass either.

Wet clippings clog the deck, discharge chute, and collection box. The motor works harder to cut through damp grass, and electric mowers may struggle or overheat.

Grass stuck to the underside of the deck promotes rust and corrosion. If not cleaned off promptly, it hardens and becomes difficult to remove.

For petrol mowers, wet grass increases the load on the engine and blade, accelerating wear.

When Wet Mowing is Acceptable

Light surface moisture from morning dew or a brief shower is manageable. The grass blades are damp but the soil is firm.

Wait a few hours after rain for the worst moisture to evaporate. Even partial drying significantly improves results.

If grass is getting unmanageably long and no dry weather is forecast, mowing wet is better than letting it grow even longer. Following the one-third rule becomes impossible if you wait too long.

When to Definitely Avoid Mowing

Don’t mow if the ground is waterlogged. If your footprints leave visible impressions or water pools on the surface, stay off with the mower.

During or immediately after heavy rain, even if the grass looks manageable, the soil will be too soft.

Frosty mornings that thaw into wet conditions combine the worst of both problems. Wait until the ground has both thawed and dried somewhat.

Tips for Mowing Wet Grass

If you must mow wet grass, these tips minimise problems.

Raise the cutting height. A higher cut reduces the load on your mower and leaves a better finish on damp grass.

Mow more slowly. Rushing through wet grass overwhelms the mower and produces worse results. Slow, steady passes allow better cutting and clipping dispersal.

Cut little and often rather than waiting for long growth. Shorter wet grass is easier to manage than long wet grass.

Use a side-discharge rather than collecting clippings if your mower allows. This prevents the box clogging with soggy grass, though you’ll need to rake up clumps afterwards.

Clean your mower immediately after use. Wet grass stuck to the deck is much easier to remove before it dries and hardens.

Sharpen your blades more frequently. Cutting wet grass dulls blades faster, and sharp blades are essential for clean cuts in difficult conditions.

The Ideal Conditions

For comparison, perfect mowing conditions are: dry grass, dry soil, mild temperature, and grass that’s been dry for at least a day.

In the UK climate, these conditions don’t occur as often as we’d like. Late morning or afternoon on a dry day is typically best, allowing any overnight moisture to evaporate.

Planning your mowing around weather forecasts helps. If dry weather is predicted, wait. If rain is coming, consider mowing slightly early while conditions are still reasonable.

Electric Mower Safety

Electric mowers require extra caution around wet conditions.

Corded electric mowers should never be used on wet grass due to electrocution risk. The combination of water, electricity, and a blade is dangerous.

Cordless battery mowers are safer but still not ideal for wet conditions. Most manufacturers advise against wet use. Check your manual for specific guidance.

If you must use an electric mower on damp grass, ensure connections are dry, avoid standing water, and never mow in rain.

Recovery After Wet Mowing

If you’ve had to mow wet, help your lawn recover.

Rake up any clumped clippings that landed on the grass. Left in place, these smother grass and encourage disease.

Wait for dry conditions before mowing again. Don’t compound the stress by repeatedly mowing wet.

If ruts have formed, address them when the soil dries. Light ruts may recover naturally; deeper ones may need filling with topsoil. Our guide to levelling a bumpy lawn covers repair techniques.

A healthy, well-fed lawn recovers from occasional wet mowing stress faster than a neglected one. Regular feeding builds resilience.