The warmer weather saw barbecue fuel sales at Waitrose rise by 95 per cent in the week to 14 May 2016.
Divisional sales increased by 4.1 per cent compared to the same week last year.
Sales of Pimms - which is synonymous with cucumber - were up too, by 72 per cent on the previous year, and picnic foods also saw significant uplifts in the week, with salad sales increasing by 12 per cent, soft fruit sales by 11 per cent, and sales in the Food to Go range up by eight per cent.
Elsewhere, online sales were up by more than 10 per cent.
