Gardeners have been urged to stop watering their lawns to do their bit for the environment, says the Royal Horticultural Society.
For the first time, the gardening charity is urging people to stop sprinkling mains water to keep them green in summer.
It recommends allowing the grass to turn yellow or brown to help prevent water shortages and protect wildlife in rivers that are at risk of drying up.
The RHS previously advised that irrigating lawns was unnecessary as grass will recover but it is now calling on all gardeners to stop using the mains supply and switch to water butts or just wait for rain.
The recommendation comes after Britain experienced the fourth wettest May on record.
Lawn watering can use as much water in an hour as one person would use in a week.”
She added that many people underestimate how much water they use in daily life and do not realise that the national average is 142 litres per person.
The RHS and Cranfield University have launched a website, mains2rains.uk, where gardeners can pledge to adopt measures to save water, including installing a water butt, placing drip trays beneath pots and adding mulch around new plants.
Kate Marx from Waterwise added: “With hot and dry spells of weather projected to increase, there are many important reasons to save water, not least of all to ensure that there is enough to go around for our communities, and to protect our environment and UK wildlife.