A pilot study: Horticulture-related activities significantly reduce stress and salivary cortisol concentration of maladjusted elementary school children

Lee, M.J., Oh, W., Jang, J.S., & Lee, J.Y. (2018). A pilot study: Horticulture-related activities significantly reduce stress and salivary cortisol concentration of maladjusted elementary school children. Complementary Therapies in Medicine, 37, 6. http://dx.doi.org/10.1016/j.ctim.2018.01.004

Horticulture-related activities can reduce the stress levels and salivary cortisol concentration of elementary school children with emotional and behavioral concernsThis experimental study explored the stress-reducing effects of three horticulture-related activities (HRAs) on maladjusted elementary school children in Korea. While previous research explored the impact of HRAs on children, few studies have explored the effects of different individual HRAs. This study examined such effects by comparing changes on a stress scale of an experimental and control group and of salivary cortisol concentrations (SCC) of the experimental group over time. A reduction of salivary cortisol concentration is a physiological indication of a decrease of stress levels.

Twenty elementary school children (age 10-11) with emotional and/or behavioral problems participated in this study. The children (all female) were randomly assigned to participate in the experimental group or control group, with ten children in each group. Children in the experimental group participated in a once-a-week HRA program consisting of flower arrangement, planting, and flower pressing activities over a period of nine weeks. Each 40-minute session focused on just one of the HRA activities. The ten children in the control group participated in alternative activities with similar levels of concentration and interest to those of the HRAs at the same time as the experimental group. All activities for both groups were conducted indoors.

Before and after participating in the HRA or alternative activities, children from both the experimental and control groups completed the Perceived Stress Scale (PSS) questionnaire which includes four subscales: Interpersonal relationships, School life, Personal problems, and Home life. Researchers also collected saliva from the experimental group one week before the HRAs and immediately after the HRA activities for each weekly session. For the control group, saliva samples were taken before and after the nine-week study period. Saliva samples were frozen immediately after collection and sent to a certified institution for analysis of salivary cortisol concentration (SCC).

Pre-assessment PSS scores showed no significant differences between the control and experimental groups. Post-assessment scores, however, showed differences between the two groups. For the experimental group, there was a decrease from the pre- to post-assessment in all four subscale areas: interpersonal relationship, school life, personal problems, and home life. The change in stress score of school life for the experimental group was significantly reduced. Results for the control group, on the other hand, showed an increase in the stress scores of several areas -- interpersonal relationships and school life.

Results of the saliva analysis showed that each of the three HRA activities were effective in decreasing cortisol levels compared to measurement of cortisol prior to the initiation of the HRA series. There were differences, however, between the activities. For the flower arrangement and flower pressing activities, the decrease in SCC was significant at the first testing. For the planting activity, the significant difference didn’t occur until the second testing.

This research indicates that HRAs can reduce the stress levels of maladjusted female elementary school children. This research also provides clues for planning high-efficiency horticultural therapy programs.

The Bottom Line

Horticulture-related activities can reduce the stress levels and salivary cortisol concentration of elementary school children with emotional and behavioral concerns