The Wakefield-based business, which runs 268 stores, tested concessions in three garden centres last year and plans to open 15 to 20 concessions in the next year, many of which will also be in garden centres.
Bonmarche said pre-tax profits jumped 66% to £8 million in the year to March 29 while like-for-like sales rose 10.4% as it also benefited from a store refitting programme.
The results are the first since Bonmarche floated on the stock market last November and represent a turnaround for the business which was sold in 2012 as part of the collapsed Peacock group to private equity business Sun European Partners.
The firm, which is chaired by the former Tesco deputy chief executive Tim Mason, carried out its garden centres trials at Lechlade, Bicester and Andover.
Bonmarche chief executive Beth Butterwick said that gardening was the fourth most popular activity among its customers and shoppers at these concessions tended to be "slightly more affluent."
In the new financial year it plans to add five stores to its estate.
The business said sales from its website leapt 84% last year, and it is working on mobile and tablet capabilities this year.