"In America they will try out new things and work till two or three in the night to get it done," he said. "Here, people prefer the familiar."
The re-landscaping of Trentham Estate, where Oudolf worked with landscaper Tom Stuart-Smith, "took ten years," he said. "And Germany is very difficult due to the bureaucracy - there is no flexibility."
Oudolf is currently working on New York's High Line project to landscape a 2.3km section of disused elevated railway. "The secret is to repeat the planting," he said. "With 18-inch (45cm) soil depth, it's basically a roof garden."
A retrospective of Oudolf's work continues at the Garden Museum until February.