A gardening expert has warned that millions of people are mowing their lawns at the wrong time of day. This could be inviting weeds, yellow patches and fungal diseases that take a long time to fix.

According to Ivana Agustina, Head of Project Management at ShrubHub, an award-winning online landscape design service, homeowners regularly cut their grass at the incorrect time. The hour you choose to do it can play a pivotal role in your lawn's health. Ivana said: "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."

In the Spring, Ivana said the best time to cut grass is between 9am and 11am. This is because the morning dew would have lifted, meaning the grass is dry enough for clean cuts.

Meanwhile, the temperature is still cool enough to avoid stressing the blades. Ivana said: "Mowing during late morning means you’re not clogging your mower with wet clippings or baking the lawn in midday heat."

However, the worst time to cut grass during the spring is before 8am and between 2pm and 4pm. If you cut your lawn while the grass is still wet, it leads to uneven trimming. 

Equally, if you wait too long in the day, you risk hitting the hottest time. This will negatively impact your lawn's moisture retention.

During the summer months, Ivana stresses that "earlier is better". She explained that the best time to cut grass in the summer is between 6am and 8am because the air is cooler and the grass is dry from the night before.

Ivana said: "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."

The worst time to cut your grass during the summer is between 12pm and 4pm. Ivana explained: "You’re slicing into already-dry blades under a blazing sun. That kind of trauma leaves your grass vulnerable to pests, yellowing, and fungal infections."

Cutting grass during wet periods can create the perfect environment for fungus to spread. It can also cause ragged and torn edges, which leads to an uneven finish and weaker grass.

Ivana said: "People usually assume mowing is just about keeping the grass short, but timing plays a much bigger role in the overall health of your lawn. When you mow during the hottest part of the day or while the grass is still wet, you're putting unnecessary strain on it, and that stress builds over time.

"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. Simply shifting your schedule by a couple of hours can help your lawn stay resilient against weeds, disease, and heat damage.

"Lawns are surprisingly forgiving, though. If you've been cutting at less-than-ideal times, there's still plenty of opportunity to adjust your routine and start seeing real improvements this season."