Associated Independent Stores (AIS) takes over GRO after the GCA was unable to generate a sustainable number of members for the scheme.
AIS, which collaborated with the Garden Centre Association (GCA) to launch the Garden Retailers Organisation (GRO) in December 2007, has now taken over the buying group and will open the scheme up to non-GCA members.
The new buying group, which is reported to start in August under the name Insideout will concentrate on a wider range of products, including housewares, giftware and soft furnishings.
A GCA spokesperson said of the move: "Unfortunately we didn't have the takers from the GCA alone so it was only fair for AIS to open it up to newcomers.
We still have the relationship - there is absolutely no hard feeling, it was purely a financial decision."
AIS is the largest non-food buying group in the UK, with a membership of 270 independent department stores and specialist retailers across the UK.