In the present research, the psychological state of elderly people in the process of raising plants from seedlings and bulbs was analyzed by means of brain waves and the semantic differential technique. Subjects were ten elderly individuals and ten young individuals. Each subject raised four kinds of plants (hyacinth, pansy, Italian parsley and candelabra cactus) for ten weeks in his or her house. Subjects raised the hyacinth from bulbs and the pansy from seedlings. At the starting, second, sixth, and tenth weeks of the experiment, the psychological state of the subjects upon seeing their plants in front of them was evaluated. The ratio of alpha waves to beta waves was calculated as an index of the degree of calmness of psychological state. In the elderly subjects, the differences in the ratios of alpha waves to beta waves between the evaluated plants became smaller over time. The influence of the bloom of the pansy on the elderly subjects' psychological state was observed. An increase in the second factor score of the pansy evaluated by the elderly subjects was also observed and this indicated that the elderly people's psychological state was changed by the blooming process of the plants.