Marks & Spencer is selling his blueberries next month - just as the rest of the UK season is coming to an end.
Mitchell established that the northerly location of his Castleton Farm, which is in Laurencekirk, Kincardineshire, is ideal for late-season blueberries.
He said: "We are close to the coast so do not get too hard frosts in the winter and extreme heat in the summer. The plants have been in the ground for a while but are just coming into fruition now."
Mitchell started growing soft fruit after running a pick-your-own business at home and seeing the potential for expanding his business into commercial supply.
He also grows 41ha of strawberries and 7ha of raspberries and is hoping to expand his empire by growing cherries too - having this year planted a 1ha trial plot of eight different varieties.
But he added that like many growers this year (Grower, 30 July) the returns from his strawberry crop have been "pretty terrible" due to the late season and an excess supply of fruit. He said: "It has been one of the worst on record."
Grower Stephen MacGuffie of New Farm Produce in Staffordshire, agreed: "If you have a late spring - and this year it was cold in May - you can be sure that your 'early' crops will crop the same time as your late crops and so many crops will be at the same time. It's even worse for growers who have not had the best-quality fruit."