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Can You Mow Wet Grass? Is It Good for Your Grass

Are you searching online whether you can you mow wet grass or not? You should never mow wet grass. Wet grass not only dulls lawn mower blades, and damages your ground, but helps to spread disease and poses a significant risk to your own safety while mowing.

In this article, we’re going to cover all the reasons why you should never be mowing grass when wet, and what levels of moisture can be tolerated by lawn mowers.


Can You Mow Wet Grass? Is It Good for Your Grass

Can You Mow Wet Grass?

Can You Mow Wet Grass

The simple answer is no, you can’t mow wet grass. While professional groundskeepers for golf courses, tennis courts and stadiums are likely to suggest that cutting wet grass is safe, it’s worth considering why they cut wet grass, and how they do it.

Professional groundskeepers have ride-on zero-turn mowers, which are designed to collect and trim grass to specific heights. Their wide blades aren’t suited to domestic lawns and work very differently.

If golf lawn keepers had the choice, even with the proper tools they would still, in all honesty, prefer not to mow in the rain, because mowing in the rain creates uneven cuts, and can tear roots from the soil.

Cutting Grass in the Rain

One of the most common questions we get asked is whether you can cut grass in the rain, and the simple answer is no. The more complicated answer is that if you’ve already started and the rain isn’t too heavy, it’s best to finish the job.

So, finish a basic cut of your lawn before it gets too wet, and clean your lawn mower quickly afterwards to avoid mould, or clumps of lawn damaging the lawnmower.

For ongoing rain on wet ground, it’s really not safe to cut your lawn, and will likely cause damage to the soil.

Mowing Lawn After Rain

Mowing Grass When Wet

Never mow after rain. Lawns hold moisture, and their dense leaves are covered in drops of water for up to two hours after rainfall. Lawn thatch holds moisture so well that on thicker lawns like rye or fescue they can create sponges beneath the surface of the grass for three or four hours after rainfall even in summer. Do not cut grass after rainfall.

Cutting Grass with Morning Dew

Morning dew is different to rain, in that it doesn’t soak the ground beneath the grass. If you can avoid cutting grass early in the morning when it has a layer of dew, then do.

But if you absolutely must, it is ok to cut grass with morning dew without damaging your lawn mower, but you will get an uneven cut, with some blades of grass popping back up later in the day that have been flattened below the blades, rather than cut.

Why You Shouldn’t Cut Grass When Wet

Below, we list the main reasons why you shouldn’t be cutting grass when wet because there’s no point in us telling you not to do something if we can’t back it up with evidence!

  • Mowing wet grass spreads disease
  • Electric mowers are not safe on wet grass
  • Wet grass can catch on lawn mower blades
  • Damp grass will clog your mower
  • Wet grass doesn’t cut well
  • Cutting wet grass can damage the ground

Mowing wet grass spreads disease

One particularly frustrating fungal disease that affects grass, Brown Patch disease, is spread far faster in wet conditions, and cutting wet grass with early signs of brown patch disease can spread the fungus right through your lawn. 

By cutting wet grass you risk spreading fungal diseases like brown patch disease right through humid lawns at any time of year.

Why You Shouldn’t Cut Grass When Wet

Electric mowers are not safe on wet grass

For obvious reasons, electric lawn mowers shouldn’t be used in the rain. Electricity and water don’t mix, and even after rain, wet grass can clog up blades.

While it’s never safe to cut across mower wires, cutting lawn mower wires in the rain is extremely dangerous. If you are in the market for a new one, be sure to check out our complete buying guide on the best electric lawn mowers available today.  

Wet grass can catch on lawn mower blades

Wet grass catches on lawnmower blades, and sticks to itself, literally tying your mower in knots. This can jam the lawn mower and cause sudden halts which can kick back.

Anything that causes the lawnmower to come to a sudden halt is dangerous as you can trip over, or stumble when this happens.

Damp grass will clog your mower

Wet grass or damp grass often fails to pass through into the collection basket creating a web of soggy clippings behind the mower blade which will need cleaning after you’ve finished cutting.

Not only do these clippings gum up the blade, reducing its sharpness, but they can often cause blockages in the mulch bag, meaning grass builds up after the blade, dragging across other grass as you walk, doing severe damage to your lawn in extremely damp conditions.

Wet grass doesn’t cut well

Even if you’re still thinking “Well, I can manage, how hard can it be?” Remember that cutting wet grass gives terrible results. Wet grass cuts unevenly, and clumps of taller grass will be pushed under the mower rather than cut, leaving clumpy, uneven lawns as a result when the weather dries out.

Cutting wet grass can damage the ground

Wet soil is loose than dry soil beneath the grass, and has less of a hold on roots. That coupled with the sticky grass blades can cause your lawn mower to pull whole chunks of grass and its roots out of the ground leaving divots and bald patches on your lawn.

Mowing Wet Grass Frequently Asked Questions

Cutting Grass with Morning Dew

Can you cut zoysia grass in the rain?

Zoysia grass cuts better when it is slightly moist as the wide, matt, grass blades are better lubricated. However, there is a very important distinction between “slightly moist” and “wet”.

The best time to cut zoysia grass for the most even cut is in the morning at around 9-10 am, when there are still some traces of dew left on your lawn.

Get to know more about zoysia grass in our comprehensive guide on how to grow grass

Why should you not cut wet grass?

Wet grass is dangerous for gardeners, causing lawn mowers to kick back, damaging lawns, and causing ongoing damage to lawn mowers. There are no circumstances where you should cut grass in the rain, or shortly after rain.

How long should you wait to cut grass after rain?

You should wait for at least 4-5 hours after rainfall to cut grass. Ideally, cut the grass when there is no sign of moisture on the leaves, and no moisture held in the thatch. 

Do wet grass blunt mower blades?

Wet grass does not blunt lawnmower blades, but it does coat them in a slimy substance that can grow mould and requires cleaning as soon as possible after cutting.

The blades themselves are generally unaffected by wet grass but become less effective if they are not cleaned.

When does morning dew dry?

Morning dew is usually dry by around 11 am, and in summer when the sun rises at 5-6 am, morning dew can often be dry by 8 am for a quick cut before work! 

What is the best time of day to mow grass?

Lawns are best mowed in the mornings, or in the early evening when the sun is lower in the sky, this allows them to heal from their cuts without drying out too quickly.

Cutting grass in the afternoon, or around midday can cause brown patches unless you follow mowing with a gentle water.

Verdict on Can You Mow Wet Grass

As I think we’ve proved, you should not mow wet grass. It is never a good idea to cut grass during or after rain, and even morning dew can damage your lawn and your lawnmower.

Take care when watering, and remember that your lawn isn’t going to die from a few days of rain without cutting. If you’re in the middle of a week-long rainfall, it’s much better to skip a week of cutting than damage your lawn trying to cut it in the rain.

About the Author Mabel Vasquez

Mabel has enjoyed a long career as a horticulturist, working in nurseries and greenhouses for many years. Although she loves all plants, Mabel has developed a particular passion over the years for herb gardens and indoor plants. Mabel has since retired from her horticulture career and loves sharing her many years of experience with our audience here at Sumo Gardener.

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