Monty Don has issued a warning to gardeners about mowing their lawns during the current heatwave, advising them to wait until at least Sunday, June 21, the summer solstice. Temperatures are set to reach 34C in parts of the UK, prompting amber heat health alerts for eastern, southeastern, and southwestern England, as well as London.
Why Mowing Should Be Avoided
According to experts, cutting grass during extreme heat and drought places significant stress on the turf, making it vulnerable to scorching, disease, and extended browning. Monty Don, presenter of Gardeners' World, encourages people to avoid mowing altogether until after the longest day on June 21. This allows bulb foliage to die back and feed next year's flowers.
Don explains: "By June a million gardens are regularly humming - and at times unpleasantly roaring - with the sound of motor-mowers keeping the grass trim and under control. But at Longmeadow we restrict this to paths and try and let as much grass as possible grow long and planted up with spring bulbs and wildflowers. This looks beautiful and is so much better for insects and all forms of wildlife than a neatly mown lawn."
Benefits of Delayed Mowing
Leaving the lawn untouched now will result in a healthier-looking garden next spring. Don advises that grass should not be cut until after June 21. If it has been hot and dry, the first cut can be made then, but sometimes he leaves it as late as mid-August. When cutting long grass, all clippings should be collected and composted to prevent adding nutrition that encourages coarser grasses.
Jonathan Davis, a grass specialist at Lawnsmith, echoes this view: "Importantly, no one should be cutting their grass this weekend. While it might seem like a good idea, the best thing you can do is leave your lawn alone during heatwave conditions. Cutting it during hot weather can place stress on the blades and lead to long-term damage."
If You Must Mow
If you cannot resist mowing, Davis recommends doing so before 10 am when temperatures are cooler. Raise the lawnmower blades to the highest setting to keep grass around three to four inches long. This length provides shade that helps retain soil moisture and protects against scorching.
Heatwave Details
The Met Office reports that parts of the south and southeast are likely to meet heatwave thresholds this weekend, with a 40% chance of exceeding the highest June temperature of 35.6C set in 1957 and 1976. East Anglia could see 32C on Friday, with temperatures rising again on Sunday to 32C and possibly 34C on Monday. These temperatures are "pretty unusual even for the middle part of June," according to Met Office meteorologist Alex Deakin.
Deputy chief forecaster Gregory Wolverson notes that the hot spell may not bring wall-to-wall sunshine; cloud and high humidity could make conditions feel "rather oppressive at times." The UK Health Security Agency's amber health warning indicates increased demand on health and social care services, with those aged 65 and over and those with health conditions most vulnerable.
A heatwave is defined as three consecutive days with daily maximum temperatures meeting or exceeding location-specific thresholds.
