They are being grown in increasing volume by the 76 members of KG Growers, whose marketing arm KG Fruits has enjoyed an exclusive trialling and marketing agreement for the last eight years and accounts for 40% of the soft fruit industry.
Leading the drive is the Jubilee strawberry, which increased this year from 61 hectares to 145 hectares, and now accounts for more than a third of KG's production. Originally only available in Marks & Spencer, it is now sold in all multiples.
A similar pattern is emerging for raspberries, where Driscoll varieties such as Isabel and Maravilla, which account for 90% of the total fruit grown by KG. Significantly, these are primocane varieties, which allow dual cropping: once in the autumn and again the following spring.
The result, according to chairman Angus Davison, is that eventually raspberries will be available over a 20-week season, rather than the current five-week peak from May to July.
Davison added that KG is now investing over £1m a year in fruit research and development, which also includes blackberries, blueberries and cherries.
Reviewing the season, Nick Marston, MD of KG Fruits, said: "After a late start with strawberries, we have pulled ahead of last year. Growers experienced a disappointing start with a high proportion of misshapen berries, but the good weather promises well for everbearers which will continue until the autumn."
Year-on-year, average prices have been static at £3.26/kg into the retailer. Raspberries have shown a rise from £6.12/kg last year to £6.53, with more rises possible. Total volumes have risen by 24% from only a 10% increase in acreage.