We're only three days into May and already the weather has been glorious, breaking records for the hottest days of the year right at the start of the month. It's made the perfect sunny, warm weather for going outside to mow the lawn too - but experts are urging people to do exactly the opposite: don't cut your grass or mow your lawn this Bank Holiday weekend. In fact, don't cut it at all in May.

The warning has been backed by renowned naturalist Sir David Attenborough, who has called on Britain to ‘delay mowing’ in the summer in a call backed by wildlife experts. It's because insects like bees, butterflies and even wasps use lawns and, in particular, the daisies, weeds and wildflowers among them, to breed, pollinate and otherwise maintain a healthy ecosystem at this time of year.

Shredding the grass down interferes with all that, killing off lots of insects that are an essential - and increasingly threatened - part of our ecosystem.

Put simply, if those insects die off, we all die off eventually.

UK wildlife organisation Plantlife said: "We’ve lost approximately 97% of flower-rich meadows since the 1930s, and with them gone are vital food needed by pollinators, like bees and butterflies.

"But your lawn can help! A healthy lawn with some long grass and wildflowers benefits wildlife, tackles pollution and can even lock away carbon below ground. With over 20 million gardens in the UK, even the smallest grassy patches add up to a significant proportion of our land, which, if managed properly, can deliver enormous gains for nature, communities and the climate.

"Lawns left long between April or May until mid-July, followed by simply mowing regularly afterwards, will go straight back to that green carpet look for the rest of the year."

Sir David Attenborough said on BBC's Wild Isles nature documentary about the UK: "Nowhere here is richer in wildflowers and insect pollinators than our traditional hay meadows. Sadly, in the last 60 years, we've lost 97% of this precious habitat.

"But with nature-friendly farming, meadows can be restored to provide a haven for wildlife.

"It's all about the timing. Delaying mowing until mid-July allows birds and insects to complete their breeding and flowers to set their seed."

Monty Don has previously given the date of June 21, whereas Sir David opts for mid-July, which would be July 15. Certainly, the longer you can go from now to July 15 the better.

Several groups and authorities across the UK have pledged to take part in No Mow May 2025.

Stratford-on-Avon Council said: "In 2025, Stratford-on-Avon District Council will again be participating in No Mow May, an important environmental initiative that aims to help reduce the global decline in pollinating insects.

"Over 80% of crop species grown in Europe rely on bees, thrips, wasps, beetles, moths and other insects for reproduction. We rely on a pollinator for every one in three bites of food we eat!

"No Mow May encourages landowners to reduce their mowing frequency during one month, which will allow plant species to flower and provide a vital source of pollen and nectar. Longer grass also provides shelter for wildlife, reduces pollution, increases carbon sequestration, and reduces carbon emissions by lowering fuel use."

North Northamptonshire Council has also confirmed it will take part. It said: "North Northamptonshire Council is once again taking part in ‘No Mow May’ this year, while continuing to implement its wider Pollinator Strategy, adopted in August 2022. This strategy forms part of the Council’s commitment to enhancing biodiversity and supporting pollinator populations across parks, open spaces, and road verges."