As the COVID-19 pandemic drags on, college students experience frustration due to the shortage of employment opportunities during the economic downturn and feel depression or even hopelessness because of anxiety about their major and career potential and their limited control over them. Against the backdrop, this study verified the effect of a non-contact horticultural therapy program that includes growing plants to reduce COVID-19-triggered hopelessness depression in college students. For this, a horticultural therapy program was provided to 153 college students for four weeks. A paired sample t-test was performed to investigate the effect of the program. The main findings of the study are as follows: the horticultural therapy participants showed a significant decrease in hopelessness depression. This study has significance in presenting practical implications by applying a horticultural therapy program to reduce hopelessness depression in college students during the prolonged COVID-19 crisis.