Gardening has a significant positive effect on health outcomes overall

A meta-analysis pooling 76 comparisons from 22 studies on gardening and health, including horticultural therapy, daily gardening and short-term experimental gardening, found an overall weighted effect size of 0.42 (Hedges' d, 95% CI: 0.36–0.48). The confidence interval did not cross zero, indicating that people who gardened showed better health outcomes than controls across measures such as depression, anxiety, body mass index, life satisfaction and quality of life.

For those shaping the built environment, this points to gardening access, whether allotments, community plots or therapeutic garden spaces, as a plausible route to measurable, if modest, gains in occupant or resident wellbeing. It bears on planners, facility managers and healthcare designers weighing whether to incorporate or preserve growing spaces as part of a site's health-supporting features, alongside other environmental provisions.

The evidence is well supported by a pooled analysis across many studies and outcome types, with the confidence interval clearly excluding zero. However, the underlying studies show significant heterogeneity, meaning effect sizes varied across contexts, and the researcher Masashi Soga and colleagues note publication bias was detected, though positive effects held after correction. The design compares gardeners to non-gardeners or before-and-after gardening, which cannot fully rule out other explanations for observed differences.