He went to a local plant nursery and bought planters. He filled his supply closet with craft sticks toothpicks felt construction paper colored string and imitation grass. Then he asked the boys to bring in twigs from trees or bushes in their yards. The goal: to build a mini tree house. Each boy planted his twig in a flowerpot and the fun began. Whenever there was 20 minutes left at the end of class the craft supplies would come out and the boys would work on their projects. In the beginning they concentrated on building a basic structure but as the season progressed the tree houses became increasingly complex with each student adding details limited only by his imagination.