At the Lamar County Adult Probation Program in Paris, Texas, a three-year study (Spring 2001-Fall 2003) involving 376 probationers was conducted to investigate the rehabilitative effects on probationers of a horticulture vocational training program. Data were collected on 189 adults who were randomly assigned to a horticulture group doing greenhouse plant production and vegetable gardening activities. The horticulture group was compared with 187 adults who were in a non-horticulture community service group doing trash clean-up and janitorial work. Within the horticulture group, significant improvement occurred in horticultural knowledge (KSU General and Specific Horticulture Exams), self-esteem (Rosenberg Self-Esteem Scale), and environmental awareness (Environmental Response Inventory). These changes did not occur within the non-horticulture community service group. Future research will examine recidivism rates and vocational placements of probationers from both groups.