Top gardeners advise use of tougher varieties that can cope with extremes of heat and cold as conditions disappoint growers

Gardeners are being urged to grow plants that can cope with extreme heat and cold after the Royal Horticultural Society was bombarded with letters from members asking why species they had cultivated successfully for years were now dying.

“It seems to be because of the temperature fluctuations,” said Nikki Barker, a senior horticultural adviser at the RHS. “We’ve gone from severe drought with an initially very mild autumn that turned cold. It’s the combination of weather patterns rather than one single event. And plants find it hard to deal with that fluctuation.”