The UK heatwave has produced a glut in strawberry, cherry and blueberry harvests prompting a wave of discounts in stores and lower prices for British farmers. Strawberry farmers said they were picking as much as 30% more fruit than usual, and blueberry growers at least 50% more this week as temperatures topped 40C on Tuesday in some parts of England. Yields are expected to be double that of the same week last year in the week ahead. Blackberry harvests are expected to be up 80% on the same time last year this week according to the British Berry Growers association. English cherry harvests have also been brought forward by about a fortnight by the heat, catching out supermarkets who had ordered in cheaper fruit from Spain, Turkey and elsewhere to cover this week and causing a glut in stores. Extreme hot weather across a large swathe of England on Monday and Tuesday prompted many shoppers to stay away from stores, adding to overstock. Tesco said it was selling kilo boxes of cherries for £5 this week after agreeing to take surplus stock off British growers. Its usual 400g punnets sell at £3. Sainsbury’s has 800g punnets of strawberries for £3 this week and Morrisons is selling 650g for £2.69. Strawberry grower Alastair Brooks, managing director of Langdon Manor Farm near Faversham in Kent, said: “It has been the most tremendous year for soft fruit with lots of sunshine. “Strawberries and cherries have come forward quite quickly. It has been warm this week. Normally when there has been warm weather demand rises but this time it has been extremely warm and supply has outstripped demand.” He said the warm nights had encouraged strawberries to ripen faster than usual making it difficult to keep up with picking, especially as workers had been on reduced hours on some days this week because of the extreme heat. Harry Hall, managing partner of Hall Hunter Partnership which grows strawberries, blueberries, blackberries and raspberries on farms in Berkshire and Surrey, said: “It has been the definition of extreme. Last year we had the coldest April on record, this year it is the hottest July. You have got to be so resilient and robust to keep things going like never before,” he said. “The weather is definitely getting more extreme and you have to be ready for anything.” He said the group’s farms were picking between 40 tonnes and 50 tonnes of blueberries a day, when they would usually be picking between 25 tonnes and 30 tonnes a day at this time of year. His teams were also harvesting up to 350 tonnes of strawberries this week, up from an average 250 tonnes. “It has put a lot of pressure on picking and packing,” he said, with extra shifts added so that the pack house is now working 24 hours a day. He said many supermarkets had switched to selling larger than usual 1kg or 650g punnets, up from the usual 400g, to clear the stock. Cherry farmers said the glut in fruit meant lower prices for their crops as the earlier harvest had meant they were competing with cheap imports at a time when costs, including energy and fuel prices and workers’ wages, had all gone up. One cherry farmer said: “We have had a good growing season but there have been a huge amount of imports from Spain and that normally doesn’t affect us.” Simon Wells, a cherry grower based in Herefordshire, who harvests later than growers in Kent and the Midlands, said: “There was a huge volume coming off English farms as we had cheap imports from Spain and Bulgaria.” He said supermarkets were not paying more for cherries despite a surge in costs because of more competition from imports. “A lot of deals were done nine months or a year ago and there is a plan at that fixed price and that doesn’t help us in an inflationary environment,” he said.