The Garden Centre Group is reportedly taking on the management of Country Homes and Gardens, which trades as Country Gardens.
However, no new documentation has been filed at Companies House for either company, leaving it unclear as to whether this is a full financial takeover.
The news follows speculation that the Garden Centre Group, which operates from 119 centres across England and Wales, is about to be put up for sale by Lloyds Banking Group, the chain's major shareholder.
Garden Centre Group chief executive Nicholas Marshall was chief executive of the 12-strong Country Gardens before taking over the larger chain in 2008. GCG already owns 29% of Country Gardens, which turned over £15.7m in the year to December 2010.