Designed by Cleve West, the space features sculpted columns, water pipes and dry stone walling, made from a combination of traditional and modern materials.
The win means The Daily Telegraph becomes the first sponsor in the show’s 149-year history to win three times in a row.
Michael Balston, chair of the judges for the award, described the garden as an “interesting use of space”, with an open feel framed beautifully by the concrete columns.
“There are many carefully thought-out and unexpected details such as the canal that is crossed by an unconventional bridge made of rocks,” he added.
Daily Telegraph gardening editor Joanna Fortnam put the win down to a combination of the nursery men from Crocus and the designer himself.
“Cleve has won a couple of golds at Chelsea and I saw that he was ready to go that extra mile. I knew he had it in him and with Crocus he could win Best in Show,” she explained