Therapeutic gardening improves mental health for adults with chronic conditions

Getting your hands dirty in the garden might offer a moderate boost to mental health for adults managing chronic health conditions. A recent review of past research found that activities like planting and tending to community gardens help ease symptoms of depression and anxiety, though the benefits for physical ailments are less pronounced. The research was published in BMC Public Health.

Chronic health conditions encompass a wide range of long-lasting medical issues that persist over time. These include physical illnesses like cardiovascular disease, arthritis, and diabetes, alongside cognitive and mood disorders like dementia, anxiety, and depression. Managing these persistent health challenges places a heavy burden on individuals, families, and healthcare systems around the world. Because the aging global population is driving an increase in these long-term conditions, medical professionals are seeking new management strategies.

Nature-based treatments are frequently recommended to help people cope with these long-term health needs. Therapeutic gardening is one such approach, where patients actively engage with plants, soil, and outdoor environments. These programs treat horticulture as a structured leisure activity that encourages physical movement, social interaction, and a connection to the natural world. In places like the United Kingdom, healthcare providers even use a process called social prescribing to encourage patients to visit parks and community gardens.

Past research has documented various psychological and social benefits of spending time in green spaces. Public health researcher Feifei Wang of Fudan University and psychologist Szilvia Boros of Széchenyi István University wanted to quantify these benefits specifically for populations with existing medical diagnoses. They designed a study to evaluate exactly how gardening activities alter specific categories of health for adults living with chronic illnesses.

To understand the broader impact of these outdoor interventions, Wang and Boros conducted a systematic review and meta-analysis. A meta-analysis is a statistical technique that pools data from multiple independent studies to identify overall trends that a single experiment might miss. The researchers searched major scientific databases for peer-reviewed studies that tested gardening programs against a standard control group. They only included research focused on adults over the age of 18 who had at least one diagnosed chronic condition.

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The team identified 23 relevant studies that included a total of 4,535 participants, representing a large combined sample size for this specific topic. The individuals involved in these trials lived with various chronic conditions, ranging from physical pain and obesity to high blood pressure, cognitive dysfunction, and cancer. The participants were primarily older adults with an average age of about 54 years, and roughly two-thirds of them were women. The included research featured a mix of randomized controlled trials and quasi-experimental study designs.

Wang and Boros extracted the reported health outcomes from these studies and divided them into three primary categories to calculate an effect size. An effect size is a statistical measurement that tells researchers how much of a difference an intervention actually made. The mental health category included measurements of anxiety, stress, depression, overall mood, and loneliness. The physical health category tracked metrics like blood pressure and cognitive function. The general health category covered broader quality of life indicators, such as pain levels, sleep quality, and social connectedness.

When analyzing the combined data, the researchers found that gardening interventions offered a moderate improvement for mental health outcomes. Participants who spent time digging, watering, and harvesting reported fewer issues with depression and anxiety compared to those in the control groups who did not participate in the gardening programs. Many of these trials involved older adults experiencing cognitive decline, such as dementia, who seemed to benefit psychologically from the active lifestyle and socialization that community gardens provide.

The analysis revealed less encouraging results for the other two categories. Gardening activities produced relatively small effects on general health and almost negligible changes to physical health outcomes. The data did not show widespread physical improvements, such as lowered blood pressure or improved cognitive function, directly stemming from the gardening interventions. The researchers noted that while physical movement is involved in gardening, it might not be strenuous enough to dramatically alter physical disease progression in a short timeframe.

To ensure the reliability of their findings, Wang and Boros performed a sensitivity analysis using a standardized quality assessment tool. This process involves stripping away studies with a high risk of bias or low-quality methodology to see if the overall trends hold up. After removing the weaker studies, the positive effect of gardening on mental health became even stronger. At the same time, the evidence for physical and general health benefits remained weak and the results were not statistically significant.

The study comes with a few limitations related to the nature of the available research. The included trials exhibited high heterogeneity, meaning the methods, duration, and intensity of the gardening programs varied wildly from one study to the next. Some studies involved short sessions over a few weeks, while others spanned several months. This wide variation makes it difficult to recommend a specific type or amount of gardening for therapeutic purposes.

Many of the included trials also struggled with methodological challenges like selection bias and a lack of randomized participant placement. In medical research, it is difficult to design a trial where participants are blind to the treatment they are receiving if that treatment involves active physical tasks. Because participants knew they were engaging in an outdoor activity, their expectations might have influenced their reported improvements in mood, stress, and general life satisfaction.

High dropout rates in community-based interventions can also skew the results of a meta-analysis. If participants who do not enjoy gardening leave a study early, the final data will only reflect the experiences of those who liked the activity enough to stay. The researchers noted that achieving perfect experimental conditions is often unrealistic when testing lifestyle interventions in real-world community settings.

Future research will need to define standardized gardening activities to better measure their health impacts. While working with plants can support psychological well-being, the current evidence does not support using horticulture as a primary treatment for physical ailments. Medical providers looking to recommend nature-based therapies require more rigorous, uniform trials to understand exactly how different health conditions respond to specific outdoor environments.

The study, “Effect of gardening activities on domains of health: a systematic review and meta-analysis,” was authored by Feifei Wang and Szilvia Boros.