Sowing the seeds of better health

photo of a senior woman smiling while working in her garden

Katherine Rosa copes with winter's gloom by meticulously planning her summer flower garden, giddily anticipating pops of color and fragrance to shift her focus toward radiant days ahead.

"It lifts the spirit and keeps my sense of vitality alive in the dark of winter," says Rosa, a family nurse practitioner and researcher at the Benson-Henry Institute for Mind Body Medicine at Harvard-affiliated Massachusetts General Hospital, who's been gardening most of her life. "It's a little bit of joy."

Therapeutic horticulture — the practice of gardening as a means to promote better health and well-being — has existed since the 19th century. But the mind-boosting benefits Rosa reaps from digging holes, planting seeds, and pulling weeds join a veritable harvest of freshly documented health advantages.

Gardening yields much the same effects on body, mind, and soul as traditional exercise, Harvard experts say. And its appeal seems to be pollinating: as of 2015, an estimated 117 million Americans — one in three — kept gardens. Another 18 million took up the activity during the COVID pandemic, according to the National Gardening Association.

"Gardening is rarely something someone is forced to do. Most people garden because they love it," says Dr. Beth Frates, director of lifestyle medicine and wellness in the Department of Surgery at Massachusetts General Hospital. "It's an activity where you literally reap what you sow."

Bodywide bonuses

A growing body of new and established evidence offers a bouquet of reasons our bodies gravitate to gardening.

It gets you moving. A study published in January 2023 in The Lancet Planetary Health suggests that gardening simply makes us move more. Researchers split 291 adults (82% women) who hadn't gardened previously into two groups; half were assigned to a community gardening group, and the others were asked to wait a year to start gardening. Both groups took periodic surveys gauging their nutrition habits and mental health. They also wore activity monitors.

The people in the gardening group increased their physical activity levels by about 42 minutes each week, more than a quarter of the standard recommendations of at least 150 minutes per week of physical activity. The CDC lists gardening as a moderate-intensity exercise that burns about 330 calories per hour, a rate similar to hiking or dancing.

"The joy of gardening allows for physical activity that feels fun and rewarding for many, especially those who don't consider themselves athletes," Dr. Frates says. "Some people think running, biking, or swimming are the only forms of aerobic activity, but this is a narrow view. Take advantage of the gym outside your window."

It improves your diet. The same study also found that participants in the gardening group ate about 7% more fiber each day — possibly because they're eating what they're growing — compared with people who didn't garden. Average daily fiber intake among American adults is about half of the recommended 25 to 30 grams per day, so the additional 1.4 grams eaten each day by the gardening group proved substantial, researchers said. Fiber can improve digestion, inflammation, and immune response.

It may fight off illness. A 2021 study published in The Journals of Gerontology: Series A suggests that people who garden may experience less age-related decline in immune system effectiveness. They also have lower levels of low-grade inflammation common among older adults that can heighten risks for cardiovascular disease, cancer, and inflammatory diseases. "Since gardening may cut stress, that also helps our immune systems to function optimally," Dr. Frates says.

Avoid these common gardening hazards

You know you'll need a trowel, a rake, and other gardening tools for all that digging, planting, and weeding. But don't forget to add sunscreen, a hat, and gloves to the list of essentials for protecting against the activity's few but notable downsides.

While some exposure to sunlight is important to get adequate vitamin D, especially as we age, about 15 minutes a day is enough to provide what we need. If you're out in the garden for longer, apply sunscreen with a high SPF and wear a broadbrimmed hat.

Gloves place a barrier between you and poison ivy and other skin allergens that may coat or nestle against your chosen vegetation. Gloves can also protect you against a less-recognized danger: bacteria or fungi that lurk in some potting soil mixes. These germs can cause various infections through the skin and even pneumonia, if you inhale them. While the threat is very low, it's wise to wear gloves while handling potting soil. For extra protection, wear a mask, or at least point bags of potting soil away from your face while opening and pouring them.

Mental tonic

Along with potentially reducing your stress, gardening produces other key mental health benefits.

It smooths mood. Connecting with nature's calm can interrupt rumination, repetitive thoughts that can contribute to depression. A study published online July 6, 2022, by the journal PLOS One suggested that gardening lowered stress, anxiety, and depression in otherwise healthy women who attended twice-weekly gardening classes for four weeks. None of the 32 women in the study had gardened previously; half were assigned to the gardening sessions, while the other half went to art classes. They reported their levels of anxiety, depression, and stress. While both groups reaped mental health benefits, the gardeners reported less anxiety.

"Instead of focusing on the to-do list, the disagreement with a colleague, an argument with a loved one, or a difficult interaction at the grocery store, the gardener can set these worries aside to become fully immersed in the task at hand," Dr. Frates says.

It sharpens your brain. A 2019 study in the International Journal of Environmental Research and Public Health suggests even a single burst of gardening significantly improves levels of brain nerve growth factors important to staying sharp. The analysis involved 41 older adults (68% women) who spent 20 minutes tending to a garden plot. Blood samples were taken before and after the gardening activity to measure brain chemicals.

"When you're gardening, you need to be focused, and you're also relying on your memory," Rosa says. "You're continually stimulating your brain cells."

It fertilizes relationships. When your tomato plants produce far more of the fat, juicy orbs than you can eat, what do you do? Pass along the extras to friends and family members — strengthening bonds in the process, Harvard experts say. Gardening also turns into a social activity when done in community plots and with garden clubs, helping relationships bloom. "If gardening is one of your social networks, you're keeping relationships that are critically important to your happiness," Rosa says.