A study was conducted to develop and field test a greenhouse production record book and unit of instruction for growing potted chrysanthemums. Twenty high schools in Pennsylvania with horticulture departments formed the population for the study. The twenty schools were randomly assigned to four treatment levels: (1) five classes received the greenhouse record book coupled with the potted-chrysanthemum units, (2) five classes received only the greenhouse record book, (3) five classes received only the potted-chrysanthemum unit, and (4) five classes received the teacher's own instructional materials. Based on mean crop quality scores and mean test scores it was concluded that the teaching unit was effective in promoting cognitive learning about potted-chrysanthemum production. The results supported the belief that the students who received the teaching unit would score higher on a cognitive test than students who did not receive the unit. The potted-chrysanthemum unit and the greenhouse record book, when used independently, were effective in helping students to grow higher quality potted chrysanthemums. (The production record book and the evaluation test are appended.) (LRA)