Outreach programs in horticultural therapy at botanical gardens and arboreta are valuable resources to the community and to ongoing HT programs in nursing homes, special education classes, hospitals, psychiatric facilities, and other institutions and agencies. These outreach programs furnish written materials, plants, and staff expertise for existing programs and help establish new programs. Seminars and conferences are held providing information on and training in HT. There are several outreach HT programs at gardens and arboreta throughout the United States and abroad. However, currently there is very little information available for developing this type of program. This thesis provides a resource guide describing HT and how it can be incorporated into a botanical garden or arboretum. Resources from The Holden Arboretum in Ohio, Chicago Botanic Garden in Illinois, and North Carolina Botanical Garden, survey information, and literature from existing programs have been compiled suggesting possible procedures to follow in implementing a program. A slide presentation has been developed which illustrates the benefits of HT and describes the outreach HT program at Holden. / M.S.