Christopher Cattle is a retired furniture design professor from England.[67] He started his first planting of furniture in 1996.[2] According to Cattle, he developed an idea to train and graft trees to grow into shapes, which came to him in the late 1970s,[68] in response to questions from students asking how to build furniture using less energy.[67] Using various species of trees and wooden jigs to shape them,[28] he has grown 15 three-legged stools to completion.[citation needed]