The study explored methods and techniques for training mentally retarded adults to perform gardening tasks. A total of 31 subjects ages 21 to 48 (IQ range 32-89) participated in the study, which consisted of three phases. In an initial pilot study, experimentation without subjects resulted in the development of modified tools (e.g., notched yardsticks for spacing seeds and color-coded hoes with steel guards). During the second pilot study, subjects were taught to use the tools. Based on problems encountered, additional modifications were made, including the use of an earth puncher instead of a hoe for brain-injured subjects. The third study added a greenhouse operation and evaluated subjects' performance over a 10-week period on 21 separate gardening tasks (e.g., preparing potting soil, using tiller, planting seeds with spacer, and covering seeds in seed bed). Techniques of physical assistance, demonstration, verbal direction, prompting, and fading were used in instruction. Results indicated that a total of 17 tasks could be mastered by subjects with an IQ as low as 32. Subjects were found to work more productively in their own individual gardens than in a large community garden. (Author/JW)