Jim, an executive in his 50s, believed that he thrived under pressure. But his blood pressure was too high and so was his blood sugar. He had become overweight. His wife thought Jim was caught up in an overly stressful cycle of working and commuting with no real break. He felt on edge all the time.

Jim knew that he should exercise, eat better, relax more and calm his anxiety. But he was, as his wife saw, essentially stuck. So he came to see me, his doctor. I’m a medical doctor, so I could have given him prescription medication for his blood pressure, anxiety and prediabetes. But instead I prescribed a specific trial of an ancient remedy—nature therapy.

For example, I told Jim to plant four small herb plants in a window box—parsley, sage, rosemary and thyme—and to spend five minutes tending to them daily, with his phone turned off. I instructed him to tell family or friends who thought he was slacking that the time was prescribed by his doctor. And I told Jim to ask his wife for support. He’s now following his nature prescription, and he hasn’t required any new medications to improve his health.

What Nature Can Do for You

Nature can be your medicine, too. Here are some medical conditions that spending time in nature has been shown to improve—acute urinary tract infections…anxiety disorder…ADHD…cancer…cardiovascular disease…depression…diabetes…healing from surgery…musculoskeletal complaints…migraines…upper-respiratory-tract ­infections…and vertigo.

Example: In a pioneering randomized controlled study by Swedish environmental psychologist Roger S. Ulrich, PhD, post-op patients who had window views of nature from their hospital beds had improved moods, needed less pain medication, had fewer surgical complications and left the hospital sooner compared with similar patients whose rooms had no views. And these patients just looked outside.

Even just looking at pictures of plants has been shown by researchers at University of Essex in Colchester, UK, to reduce blood pressure, pulse rate and muscle tension after a stressful experience. Putting up beautiful pictures of nature—water, trees, forests or meadows—in your home (or if you are in a hospital, in your room) may sound trivial, but it’s not.

Getting outside and into natural environments is even more powerful. People who spend just 30 minutes in a green outdoor space at least once a week are 7% less likely to develop high blood pressure, and 9% less likely to develop depression, than people who spend little or no time, according to a study published in Scientific Reports.

There’s much more to nature as medicine. Here are six more powerful ways to use nature to heal what ails you…

Take a Forest Bath

What forest bathers do is walk very slowly in a wooded area for two or three hours. They may cover only a quarter mile doing this. Whenever they feel like it, they sit for a few minutes, just to sense what is around them. A contemplative, sensual immersion, forest bathing has been part of Korean and Japanese disease prevention and treatment for decades. Dozens of peer-reviewed studies show that forest therapy reduces your blood pressure, heart rate and stress hormones…and then reduces the stress you experience for days afterward.

Trees play an important role, releasing essential aromatic oils called phytoncides that boost immunity and antiviral natural killer cells. MRI brain scans find that the longer a person is exposed to trees, the less activity there is in the amygdala, the part of the brain that controls distress and fear responses, contributing to anxiety disorders and depression.

What to do: Turn off your phone. Find a wooded area and comfortable sitting spot. Don’t hurry. Tune into the sounds first: Hear the closest sound and then the farthest. Use your other senses: Watch the birds, feel the leaves, smell the breeze, appreciate the stillness. Get up and amble a bit. Become aware of your connection with the environment, which strengthens your concentration and focus.

Can’t schedule two or three hours? Try meditating for shorter periods in a natural, electronics-free setting. If you already meditate, compare how you feel when you do it in nature versus in your usual spot.

Green the Inside of Your Home

Gardening is excellent medicine for body and mind. Compared with others, gardeners tend to weigh less, are less susceptible to depression and anxiety, have greater self-esteem—and are between 36% and 47% less likely to develop dementia, research finds.

Of course, not all of us have the space to be outdoor gardeners. Plus, we spend up to 90% of our time indoors, often breathing indoor pollutants from household chemicals that can harm our lungs, heart and other organs. Solution: Garden indoors! Greenery inside is beautifying, a psychological respite—and it literally purifies the air you breathe. Studies show that indoor gardeners get similar benefits to outdoor gardeners.

What to do: Choose houseplants that are especially good at removing toxins from the air. Examples include Dracaena Janet Craig (yes, that’s the real name), Boston fern and spider plants.

Exercise Outside in a Green Space

A recent Stanford study showed significantly reduced rumination—obsessive worrying—after a 90-minute walk in nature, compared with a 90-minute walk through an urban environment. Any exercise is better than none, of course, but “green” exercise appears to be better than indoor exercise at stimulating the release of endorphins, the body’s feel-good chemicals, and triggering new brain-cell development.

It takes only five minutes of exercising in nature to boost mood and self-esteem, according to one British study. But like medications, there’s a dose-response ­effect—the more you do, the greater the benefit…without any side effects, of course.

What to do: Exercise outside or in view of nature. Take a lunchtime walk to a park.

Breathe This

Aromatherapy using plant essential oils smells good and is good for you, with proven clinical benefits. Examples…

Lavender blossom: Reduces migraine pain and improves sleep quality.

Bergamot orange: Lowers stress and improves fatigue.

Yuzu lemon: Improves premenstrual emotional symptoms and lowers heart rate.

Caution: Whether you inhale, apply or massage essential oils, allergic ­reactions are possible. To minimize risk, wear gloves and wash your hands. Use a very small amount and see how you react. And buy certified organic products to make sure that you’re not getting any pesticides. If you have a medical condition, talk to your doctor first.

There’s an App for That—and Websites, Too

Can looking at your phone be “green”? Not if it replaces being in nature. But virtual nature experiences can be beneficial during your life indoors.

What to do: Try Calm.com (Apple and Android, $12.99 a month) to improve mood and Headspace.com (Apple and Android, $12.99 a month) to learn meditation. Find ambient sounds such as waterfalls on YouTube (free) or on an app such as Rain Rain, which is great for meditation and sleep (Apple and Android, free). Connect with amateur naturalists on INaturalist.org (free). Find more free resources at my website, DrJLP.com/NatureRxLinks.

Try Pet Therapy

Most Americans already live with nature inside our homes. About two-thirds of all US households own pets, and dogs especially can provide unconditional love. Ironically, the dirt they bring into our homes may be good for our immune systems—and pets offer connectivity and emotional support to their owners, especially in times of ­crisis. That is powerful medicine. So, of course, is walking a dog. Dog owners have about one-third lower risk for heart disease than people who don’t own dogs—a benefit that’s especially strong in people who live alone.

What to do: If you don’t have a dog, borrow one! Offer to walk a neighbor’s dog, say, once or twice a week. Schedule walks in your calendar as if they were meetings. Your blood pressure will fall. So may your risk for heart disease.