Squires has exhibited at all 25 Hampton Court Palace Flower Shows. Colin Squire and Ian Hammond are designing the 2015 garden.
Sarah Squire said: "We started planning last autumn. The initial design had to be with the RHS before Christmas. The show has changed dramatically over the last 25 years. It has grown in size and stature in the gardening calendar. The quality of exhibits gets better and better every year, and the sheer scale and variety of plants never ceases to amaze me."
She said of the design: "There will be elements of silver in the planting but the varieties used will very much depend on what is looking at its peak in time for the show. That can depend very much on the sort of weather we have in the run up. We will prepare far more plants than we actually need to make sure we are only displaying the very best."
The company celebrates its 80th anniversary in 2016, which Squire will start planning this May.