Walk slowly beneath a canopy of beech and oak, and something in the body begins to settle. The Japanese call the practice shinrin-yoku — forest bathing — and the forest bathing benefits now documented by researchers range from lower cortisol and blood pressure to measurable shifts in immune function. Yet for readers of Hildegard von Bingen, the twelfth-century Benedictine abbess, physician, and composer of the Rhineland, none of this arrives as news. Hildegard had a word for the healing vitality that modern instruments now trace in our blood and heart rhythms: viriditas, the greening power of God at work in every leaf, root, and living soul. Forest bathing, one might say, is a clinical trial of an idea she named nearly nine hundred years ago.
A Practice Born in Japan, Rooted in Something Older
The term shinrin-yoku was coined in 1982 by Japan’s Forestry Agency, which proposed that time spent unhurried among trees might serve public health as a form of preventive care. Forest bathing is not hiking, and it is certainly not exercise with a step count. It is slow, aimless, sensory immersion: walking without a destination, breathing deliberately, letting the eyes rest on green light and moving leaves. The practice asks for presence rather than performance.
To anyone familiar with monastic life, this posture feels recognizable. Hildegard spent nearly her entire life within Benedictine communities set among the wooded hills above the Rhine — first at Disibodenberg, later at the monastery she founded at Rupertsberg near Bingen. Her days moved through a rhythm of prayer, work, and rest that regularly carried the community into gardens, orchards, and the surrounding countryside. The medieval monastery was, among many other things, an institution that took the natural world seriously as a companion to the soul’s health.
A slow path through the trees: forest bathing asks nothing more than unhurried presence.
What Modern Science Sees Among the Trees
The research on forest bathing has matured considerably in the past two decades. A 2026 review in the peer-reviewed journal Medical Sciences gathered the evidence on forest exposure and preventive medicine, and its findings read like a physiology of calm: time among trees is associated with reduced salivary cortisol, lower blood pressure, a shift toward parasympathetic (rest-and-digest) nervous system dominance, and modulation of inflammatory signaling.
Among the most intriguing findings is the work on immune function. Studies conducted at Nippon Medical School in Tokyo found that multi-day forest trips were followed by elevated activity of natural killer cells — immune cells involved in the body’s routine surveillance — with effects that persisted for days afterward. Researchers point to phytoncides, the aromatic compounds trees release into forest air, as one possible contributor, alongside the simpler mechanics of lowered stress.
Dose seems to matter, though not much is required. A large 2019 study in Scientific Reports found that people who spent roughly two hours a week in natural settings were significantly more likely to report good health and wellbeing than those who spent none. Two hours — less time than most of us give to a single evening of television.
A word of scholarly honesty, in keeping with this site’s habits: much of this research is young, sample sizes are often small, and no one should mistake a walk in the woods for medical treatment. Forest bathing may support wellbeing; it does not replace care. But the direction of the evidence is consistent, and it points somewhere Hildegard already stood.
Viriditas: The Greening Power Hildegard Named
No concept is more distinctively Hildegard’s than viriditas — the greening power she saw coursing through all of creation. The word appears throughout her visionary and medical writings — in Scivias, in Causae et Curae, in her letters and songs — naming the moist, fertile, divine vitality that makes plants grow, wounds knit, and souls flourish. In one of her antiphons she addresses the "noblest greenness" itself, rooted in the sun, praising a vitality that no earthly power can exhaust. Its opposite, in her vocabulary, was ariditas: dryness, the withering of body or spirit cut off from its source.
Hildegard was no vague nature mystic. Her Physica is a working catalogue of the natural world’s healing properties, and she devoted an entire book of it to trees — beech, oak, linden, chestnut — each assessed for its character and its uses. In Causae et Curae she bound human health to the elements, the seasons, and the rhythms of the created order. For Hildegard, standing beneath a green canopy was not scenery; it was proximity to the very energy that sustains life. What a modern researcher measures as parasympathetic activation, she would have recognized as the soul drinking from viriditas.
This is why the modern science of awe and wonder keeps finding that vast, green, living places quiet the self and restore the body. Hildegard thought of that — not in randomized trials, but in a theology that never separated the health of the body from the life of the spirit.
Forest Bathing with Hildegard’s Discretio
If you would like to try forest bathing in a spirit Hildegard would recognize, her principle of discretio — discretion, or holy moderation — is the best guide. Nothing here should be strenuous, optimized, or tracked.
Choose a wooded place you can reach without hurry, and give it an unhurried hour. Leave the phone in the car, or silence it completely; the practice belongs to the senses, not the screen. Walk at half your usual pace, and stop often. Notice five things you can see, four you can hear, three you can touch. Breathe through the nose, slowly, and let the forest air — phytoncides and all — do its quiet work. If a bench or a fallen log invites you, sit; stillness among trees is forest bathing too, and it shades naturally into the kind of meditation in nature we have written about before. Let the season be what it is: bare branches in winter carry viriditas in reserve, and Hildegard’s greening power is as present in first frost as in high summer. End, if it suits you, with a moment of gratitude — for Hildegard, the green world was a gift, and gratitude is the fitting response to gifts.
Hildegard’s greening power, brought indoors: herbs, amber glass, and an open page.
Bringing the Green Home
Not everyone lives near a forest, and Hildegard’s tradition never required one. Viriditas, in her understanding, could be met in a monastery garden, a pot of herbs on a windowsill, a bowl of warm spelt, or the bitter green plants of her pharmacopoeia taken before a meal. The same greening vitality that fills a beech wood is present, concentrated, in the herbs she catalogued — gentian, wormwood, fennel — plants traditionally used in European monastic practice to awaken digestion and steady the gut-brain connection that modern research now studies with such interest.
That continuity is the quiet idea behind the Hildegard formula we keep alive at Eurbal: her herbal wisdom, prepared with the same reverence she brought to the green world. However you meet viriditas this week — under a canopy, in a garden, or at your own table — meet it slowly. That, Hildegard would say, is how the greening power works: not in haste, but in the patient rhythm of living things.
If you would like to bring a small measure of Hildegard’s green tradition to your own table, her herbal bitters — inspired by the botanicals she documented — are available in Hildegard’s Bitters on Amazon.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.