With sunny weather and hotter temperatures finally on the horizon, homeowners will be starting to think about revving up their lawnmowers and giving their grass a trim ahead of summer barbecues and garden party season. Most people think that the most important factor when it comes to mowing their lawn is how short they cut it – but it is actually when they cut it. In fact, cutting your grass at the wrong time can result in yellow blades, weeds, and an over-stressed lawn.
“People don’t realise that grass gets stressed just like any plant. If you mow it at the wrong time, you’re basically wounding the lawn when it’s least able to recover,” Ivana Agustina, head of project management at landscape design service ShrubHub, said.
The time of day you should mow your lawn depends on the season. The best time to cut the grass is between 9am and 11am in the spring as this is when the morning dew has lifted and the temperature is still cool enough to avoid stressing the blades.
Agustina said: “Mowing during late morning means you’re not clogging your mower with wet clippings or baking the lawn in midday heat.”
The worst time in the spring would be before 8am or during the mid-afternoon. This is because early in the morning the grass is still wet, which results in uneven trimming. On the other hand, mid-afternoon is the hottest part of the day, which has a negative impact on water retention and lawn health.
What about in the summer? In June, July, and August, it is best to mow your lawn early in the morning – between 6am and 8am – as the grass will be dry from the night before and temperatures will be cooler.
“This is when your lawn can handle being trimmed without going into survival mode. It’s the least stressful time for the grass – and the most effective for keeping it green,” Agustina explained.
Mowing your lawn between 12pm and 4pm in the summer heat could be damaging to the grass. “You’re slicing into already-dry blades under a blazing sun,” Agustina said. “That kind of trauma leaves your grass vulnerable to pests, yellowing, and fungal infections.”
Cutting during damp periods can lead to the spread of fungus or an uneven finish and weaker grass. Weaker grass, resulting from mowing at the wrong times, can give weeds a foothold, so it is important to prioritise your lawn’s health.
Agustina explained: “We often see homeowners puzzled by patchy, yellowing grass, even when they’re following all the other rules. More often than not, the problem comes down to when they’re mowing.”
However, she added that “simply shifting your schedule by a couple of hours can help your lawn stay resilient against weeds, disease, and heat damage”.