This paper reports on a study undertaken with the primary aim of investigating the effect of the storytelling teaching approach on kindergarten children's retention of ideas about the importance of trees. The study also assessed the effect of storytelling on children's intention to participate in a tree planting activity that they had to select from a list of activities. The story that was created included such elements as binary opposites, mental images, mystery, and wonder, according to Kieran Egan's theory. The study utilized a two-group design, was conducted in three phases (pre-test, intervention, and post-test), lasted 11 weeks, and its results provide evidence of the effectiveness of the storytelling approach when compared with the traditional method of expository teaching complemented with visual images (pictures) of trees and their importance to human beings. The pedagogical appropriateness of the story, which was based upon the binary pair of opposites "security-insecurity", is also discussed in the paper. (Contains 2 notes and 10 tables.)