Tatton Park Flower Show was set up by the RHS in 1999 and attracted 102,000 visitors in its first year. This fell to 67,000 in 2014. The 2016 show will be the eighteenth annual event.
The RHS said: "With regards to RHS Flower Show Tatton Park, we regularly review all aspects of the RHS Shows, our plans for the show at Tatton continue beyond 2017. We are positive about the future of the show."
Meanwhile, Alex Denman and Anita Foy have left the RHS shows department. Denman was due back from maternity leave but has resigned, while her stand-in, Foy, has also resigned. Both are trained horticulturists.
Nick Mattingley now runs RHS shows.
The RHS said: "Alex Denman, previously RHS head of shows development, has decided not to return to the RHS following her current maternity leave.
"After nearly three years at the RHS working part time on several key projects, including as acting head of shows development, during Alex’s maternity leave, Anita Foy has decided to dedicate her attention to her own business again and she will be finishing her current fixed term contract with the RHS at the end of September.
"In early September the RHS will begin recruiting for a head of development, which will be a full time role based at Vincent Square."