The traditional English cottage garden full of roses, delphiniums and hollyhocks may soon be a thing of the past because of climate change, the government warned yesterday.

Ian Pearson, the Environment Minister, said that average temperatures would probably increase by 5.4F (3C) by the 2080s, forcing gardeners to move from traditional plants to Mediterranean varieties that could withstand dry, hot summers.

“Some gardeners will have been struggling with serious drought during the past 18 months and all of us faced July’s heatwave,” said Pearson. “These conditions will become commonplace in the future. They will put our gardeners in the front line of climate change . The quintessential English garden will have to adapt to our changing climate.”

Winters were likely to become warmer and wetter, with frosts becoming increasingly rare and an increase in extreme storms causing flash flooding and plant damage. Summer rainfall would decrease to half its current level and the warmer weather was likely to encourage more pests.

Sir Peter Crane, the director of the world-famous Royal Botanic Gardens at Kew added: “There is real cause for concern and action is needed on climate change. All of us, governments and individuals, need to cut carbon emissions to limit warming to a 2C increase or less”.