He is fascinated by the rural growth and flowering of plants and trees. As a child, he went out exploring nature in the river area around Gorinchem. In his works of art, he uses living plants and trees that he subjects to experiments and subsequently observes in order to discover which laws underlie their growth processes. He would hang a plant upside-down, for example, to see the leaves grow upward after a certain period or tie a knot in a young willow tree and record how the tree developed in the course of time in spite of or thanks to the unnatural operation.
Later on, he went on to carry out large-scale projects such as a beech palisade consisting of 250 beech trees and a 50-metre high pine wall, both planted in the National Park de Hoge Veluwe in 1985. The trees were pushed into a form within a wooden frame to further develop from there.
