The museum is within South Downs Heritage Centre, which is located at South Downs Nurseries, in Hassocks, part of the Tates of Sussex garden centre group.
Buttress said: "It’s the first time I’ve been asked to open anything like this, focusing on a subject so close to my heart. I’m thrilled to be a part of it."
Clive Gravett, curator of the Budding Foundation Museum of Gardening, said "I’m so immensely proud of how this museum has come together over these past months. I’m so grateful that we’ve been given this space to build our museum and raise awareness of our charity, so we can continue our work with these young people in need of support."
The Budding Foundation is a charity for young people, with the emphasis on helping those who have lacked support or opportunity at some stage in their lives. Gravett has linked his interest in Edwin Beard Budding, inventor of the lawnmower, to the charity’s aims in the hope young people may perhaps be as inventive as he was 200 years ago.
Entry is free to the museum, which includes old lawnmowers and other garden artefacts as well as a live bee hive.