A prospective study of existential issues in therapeutic horticulture for clinical depression.

Two studies with single-group design (Study 1 N = 18, Study 2 N = 28) addressed whether horticultural activities ameliorate depression severity and existential issues. Measures were obtained before and after a 12-week therapeutic horticulture program and at 3-month follow-up. In both studies, depression severity declined significantly during the intervention and remained low at the follow-up. In both studies the existential outcomes did not change significantly; however, the change that did occur during the intervention correlated (rho > .43) with change in depression severity. Participants' open-ended accounts described the therapeutic horticulture experience as meaningful and influential for their view of life.