A longer growing season and the effects of the fifth warmest winter on record could lead to a 10% uplift in domestic strawberry production this year, British Summer Fruits has said.

With the strawberry season starting on 13 May, some three weeks earlier than in 2013, the industry body – which represents suppliers of 98% of the berries sold to UK supermarkets – said growers were expecting a bigger and sweeter crop, despite the wettest winter in 250 years.

British Summer Fruits reported that good levels of spring sunshine had increased the speed of photosynthesis, meaning that plants were producing more sugars, and strawberries were juicier than normal.

A total domestic strawberry haul of 51,000 tonnes was expected by the end of the season, up from 46,000 in 2013, said Laurence Olins, chairman of British Summer Fruits.

“The first British strawberry of the year is the ultimate indicator that summer has arrived,” he said.

“This year strawberry fans can indulge in the treat even earlier than usual, and can look forward to an abundant supply right through to the autumn.

“More and more producers are growing strawberries in protected conditions, under glass or tunnels, so that the strawberry plants aren’t exposed to the vagaries of the British weather to ensure first-rate quality.”

Olins added that British growers could soon follow the lead of their Dutch and Belgian counterparts by using the technology to produce strawberries all year long, as supermarkets and consumers demanded home-grown produce.

This year’s strawberry season is expected to extend into late October and early November.

Total British berry sales have more than doubled to £805m in the 10 years to 2012, according to Olins.