Hummelo is a village and private garden in Gelderland, eastern Netherlands. It is also Piet Oudolf’s home, his personal garden laboratory, a former nursery run by his wife Anja, and the place where he first tested new designs and created the new varieties of perennials that are now widely available.
Piet Oudolf is an influential Dutch garden designer, nurseryman and author. He is a leading figure of the "New Perennial" movement, using bold drifts of herbaceous perennials and grasses which are chosen at least as much for their structure as for their flower color. Other noteworthy Oudolf projects include The Highline and The Battery in New York City.
Oudolf first moved into Hummelo in 1982. It has gone through many changes which reflect Oudolf's constantly developing planting design.
Sources:
http://oudolf.com/
http://www.monacellipress.com/book/?isbn=9781580934183