Is gardening good for your health?

What gardening adds

Gardening combines moderate movement, time outdoors, a sense of purpose, and often social contact and fresh food. A meta-analysis of 22 studies found it linked to less depression, anxiety and body mass index (BMI), and to more life satisfaction, quality of life and sense of community; the studies showed signs of publication bias, though the effect held after adjustment¹.

Stress in the moment

After a stressful task, 30 gardeners were randomly assigned to 30 minutes of gardening or reading. Cortisol, a stress hormone, fell more with gardening, and positive mood was fully restored³.

The best trial so far

The Community Activation for Prevention study randomized 291 adults on a Denver-area waiting list for community gardens to receive a plot or keep waiting². Over a season, gardeners ended up with about 1.4 g more fiber and 5.8 more minutes of moderate-to-vigorous activity a day than waiting-list participants, though the estimates were imprecise, and they had larger drops in stress and anxiety; BMI, waist size and combined fruit and vegetable intake did not differ significantly².

Food, weight and lifespan

In Denver, community gardeners ate fruit and vegetables 5.7 times a day versus 3.9 for non-gardeners⁵. In Salt Lake City, community gardeners had BMIs about 2 points lower than their neighbors¹⁰. In a national US survey followed for about 17 years, people who gardened had a 24% lower risk of death⁴. These are observational findings: people who choose gardening may be healthier or more motivated to begin with, and a systematic review found that most collective-garden studies were cross-sectional with selection bias¹¹.

Risks to manage

Ticks, soil and sun are the main hazards. Checking for ticks and bathing soon after yard time were linked to less Lyme disease⁶. Gardeners' sun exposure depends on when they work; in a dosimeter study, the group with lower doses may have benefited from indoor breaks at peak sun¹². Compost and potting mix can carry Legionella longbeachae⁷, tetanus bacteria live in soil⁹, and garden tools injure eyes⁸.

Before you grow food, read Lead and Other Contaminants in Garden Soil. Whether soil microbes add anything beyond the activity, fresh air and company is early, unproven science; see Dirt, Soil Microbes, and Immune Health.

Pooled evidence

Soga and colleagues meta-analyzed 22 studies (76 comparisons), mostly from the US, Europe, Asia and the Middle East, comparing health outcomes before and after gardening or between gardeners and non-gardeners¹. Outcomes included reductions in depression, anxiety and BMI and increases in life satisfaction, quality of life and sense of community¹. Egger's test showed publication bias, but the positive effect remained after trim-and-fill adjustment¹. Limitation: the controls were people before they started gardening or non-gardeners, not randomized groups.

The randomized trial

In the CAPS trial, 493 adults were screened and 291 who had not gardened in two years were randomized 1:1 to a community garden plot (145) or a waiting list (146)². Mean age was 41.5, 82% were women and 34% Hispanic; data collected after February 2020 were excluded because of the pandemic, leaving 237 participants (81%) with measures before it². Time-by-intervention effects were significant for fiber intake (p=0.034; between-group difference 1.41 g/day at the autumn timepoint, 99.5% CI -2.09 to 4.92) and moderate-to-vigorous activity (p=0.012; 5.80 minutes/day, 99.5% CI -4.44 to 16.05)². There were no significant effects on combined fruit and vegetable intake, the Healthy Eating Index, sedentary time, BMI or waist circumference, but perceived stress and anxiety fell more in gardeners². Limitations: a waiting-list control, partly self-reported outcomes, and strict-threshold confidence intervals that cross zero, so the effects are small and imprecise. One gardener had an allergic event.

A small experiment on stress

Van den Berg and Custers had 30 allotment gardeners do a stressful Stroop task and randomly assigned them to 30 minutes of gardening or indoor reading on their own plot³. Both lowered salivary cortisol, but the fall was significantly stronger with gardening, and positive mood was fully restored after gardening but worsened during reading³. Limitations: 30 experienced gardeners, one session, acute effects only.

Observational studies and their weaknesses

Litt and colleagues' Denver survey of 436 residents in 58 block groups found that community gardeners ate fruit and vegetables 5.7 times a day, home gardeners 4.6 and non-gardeners 3.9, and that 56%, 37% and 25% respectively met the five-a-day recommendation⁵. Zick and colleagues compared 198 Salt Lake City community gardeners with neighbors, siblings and spouses; BMI was lower than neighbors' by 1.84 in women and 2.36 in men, and lower than sisters' by 1.88 and brothers' by 1.33¹⁰. In the NHANES cohort of 13,812 adults followed for a median 16.8 years (3,476 deaths), gardening was linked to lower total mortality (hazard ratio 0.76, 95% CI 0.68-0.85), cardiovascular mortality (0.65, 0.53-0.80), cancer mortality (0.81, 0.67-0.99) and respiratory mortality (0.66, 0.45-0.98), with more frequent and longer gardening linked to lower mortality⁴. A systematic review of 15 urban collective-garden studies found higher fruit and vegetable intake, mixed results for activity and physiology and mostly positive mental and social health, but 13 of 15 were cross-sectional with selection bias and only three used objective measures¹¹. Notably, the trial did not reproduce the fruit-and-vegetable gap seen in surveys, a sign that self-selection may inflate cross-sectional associations.

Hazards

In a Connecticut case-control study of 364 people with Lyme disease and 349 matched controls, checking for ticks within 36 hours (odds ratio 0.55, 95% CI 0.32-0.94) and bathing within 2 hours (0.42, 0.23-0.78) of yard time were protective, as was fencing (0.54, 0.33-0.90)⁶. UV dosimeters worn by 53 gardeners for four summer months showed median work-day doses of 0.97 standard erythema doses in Irish and 1.6 in Danish gardeners, with the authors suggesting that the lower exposure may reflect indoor breaks at peak UV¹². In a New Zealand case-control study (31 cases, 172 controls), Legionella longbeachae disease was linked to COPD, smoking for more than 10 years and exposure to compost or potting mix, particularly unwashed hands near the face after handling it; masks and gloves were not protective⁷. US surveillance recorded 233 tetanus cases in 2001-2008, with a 13.2% case-fatality rate among those with known outcomes, and of 51 patients with an acute wound and enough data, 49 had not received appropriate prophylaxis⁹. Garden-tool eye injuries accounted for an estimated 9,326 US emergency visits over 2014-2023, about half of them contusions or corneal abrasions, most often caused by debris⁸.

Bottom line (confidence 3 of 5)

Gardening is a sensible, low-cost way to move more, spend time outdoors and ease stress, and the evidence leans positive. But trial effects are small, many studies are self-selected, and the hazards need basic precautions. Gardening is not a treatment for any disease.