Key Points
- Wet grass clumps in the mower, affecting grass dispersal and potentially stalling the mower.
- Buildup of wet grass clippings kills the lawn when not picked up.
- The surface of wet grass is unsafe and slippery, and can lead to accidents with the lawn mower.
While many gardening tasks are best done early in the day when temperatures are still cool, mowing is not one of them. In the morning, the grass is still wet from dew. Getting out the lawn mower and cutting your grass has a damaging effect on both the lawn mower and the grass, as well as your safety.
Find out exactly why mowing too early in the day is not a good idea, and get tips for when to mow your lawn instead, plus other pro lawn mowing advice.
Why You Shouldn’t Mow Too Early
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There are several reasons why mowing wet grass is a bad idea.
Unlike dry grass, which easily disperses out of the shoot, dewy grass clumps up in the blade housing, which impedes the proper discharge of the cut grass. Wet grass cuts unevenly, tearing the grass blades and leaving them open to disease.
Grass clippings clump on the lawn and need to be removed, whereas thinly dispersed dry grass clippings are best recycled back into the lawn. Not to mention cleaning up the mower with wet grass stuck to it is a chore.
Mowing wet grass is unsafe. If using a walk-behind mower, you might slip on the wet grass, and your foot can get caught underneath the blade housing, resulting in severe injury. A riding mower might also slip and topple over.
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The Best Time to Mow
If you want to mow in the morning, wait four to five hours after sunrise or until the dew has fully evaporated. How long it takes for the grass to dry fully depends on whether the location and time of year. It takes longer for the dew to evaporate during the cooler spring and fall months than in hot summer weather.
Another good time to mow is also in the early evening when the temperature is cooler, but before nighttime moisture has developed.
Potential Damages From Mowing Too Early
Mowing too early can damage your mower, but it could also damage your lawn, too.
Damage to Mower
Grass that is wet from dew clings to the mower blade and builds up as a compacted mass in the housing around the blade. As the grass builds up, it slows down the blade movement. This puts a lot of stress on the shaft and the engine, which becomes overworked and eventually stalls, or, in the worst-case scenario, damages internal parts.
Damage to Lawn
Clumps of dewy grass cuttings are heavy and pile up unevenly on the lawn. If they are not removed promptly, they cause the grass underneath to die, and the bare spots are quickly invaded by weeds.
Because wet grass blades are torn by the mower rather than cleanly cut, they are more susceptible to diseases such as brown patch that thrive in wet conditions.
Pro Tips for Mowing a Lawn
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- Alternate horizontal and vertical passes between mowing sessions and overlap your passes by at least a wheel width.
- Get your mower blades sharpened at least once or twice a year.
- Grease the bearings of your lawn mower wheels at least twice a year.
- Mow high, which ensures a healthier lawn.
- For the last mowing session of the season, cut slightly lower to discourage mice and voles from making their home in the grass.
How to Fix a Dull Mower
Properly sharpening mower blades requires special equipment and skills. Learn how to remove the blade on your lawn mower, then take your mower blades to a hardware store for sharpening. Invest in a high-quality steel blade and have a second one as a backup when the first one is being sharpened.