Topiary and water
Wirtz (1924-2018) came to be known for designs that complemented, instead of concealing, the natural surroundings; he favoured flowering plants, grasses, clipped trees and hedges, and water rather than man-made materials, sitting in big gestures of sculptural free-form designs with free-form topiary, creating "playful organic mounds of "cloud-pruned" box, yew or hornbeam".