Dozens of the 18th century designer's landscapes will host events this summer to mark the 300th anniversary of his birth, ranging from sensory trails to art installations.
Speaking at a launch event in Westminster, Evans said: "We want people to realise the green bit between the house and the car park was as built and made as the house itself and just as worth exploring. We want these landscapes back full of people and as busy as they were in Capability Brown's time, not just this year but for years going forward."
Festival chair Gilly Drummond added that Brown was more than a "tree, grass and water man" and was also an engineer. Historic Royal Palaces chief curator Lucy Worsley said Brown started his career being described as a "cabbage planter" and ended it lauded as an artist who "adorned his country".