Thompson & Morgan have developed new potato growing bags that promise better and easier yields than their 40-litre grow sacks.

The new grow bags work with just one tuber per 8-litre bag – and the method was discovered during technical trials at T&M’s Ipswich HQ.

The small but durable bags, ideal for those without gardens, can be positioned on wide window ledges or in porches – or simply used anywhere as an easier way of growing potatoes.

T&M noted a 186% increase in yield from the bags, with a single one producing more than 80 tubers.

Amateur growers tested the bags this summer, when T & M horticultural director Paul Hansford challenged his local gardening club to a grow-off with three tubers of Maris Peer and three 8-litre bags. Gwynneth Hogger (pictured left) took the winner’s cup for her harvest of 17.5lbs of potatoes from three bags.

Paul said: “The club results were hard to believe. If I hadn’t cut the top growth from the winning entry and emptied out the crop myself, I wouldn’t have believed it. It was like the tubers were trying to burst out of the bags!”