How Often Should You Go to the Forest?

Two hours a week among trees, spread across several visits rather than saved up for one, is the most defensible answer the research currently supports. A survey of 19,806 adults in England found that people who reported at least 120 minutes of contact with nature in the previous week were considerably more likely to report good health and high wellbeing, while everyone reporting less than 120 minutes showed no such advantage. Whether those two hours arrived in one long visit or in six short ones made no measurable difference to the association (White et al., 2019).

Repetition matters more than the length of any single visit. The newest meta-analysis of forest therapy, published in April 2026, pooled 25 controlled studies with 1,876 participants and found that programmes running longer than a week reduced psychological stress close to twice as strongly as single-session exposures, with standardised mean differences of -0.93 against -0.54. When the authors tested three dose variables together, only the total length of the programme predicted the size of the effect. Sessions per week and the length of an individual session pointed the expected way without reaching significance (Pan et al., 2026).

I guide forest therapy in Slovenia and have facilitated people in nature since 2019. How often should I come back is the question I hear most on the way back to the cars, and for a long time I answered it with a shrug and a recommendation. The dose research has improved enough in the last two years to answer it properly, including the parts that are still missing. This article goes through what the pooled evidence shows about frequency and length, where that evidence runs out, and what a workable rhythm looks like in a country that is 58 percent forest. If exhaustion is what brought you here, forest therapy and burnout covers that ground in more detail.

What the newest meta-analysis found about dose

Programme length was the only dose variable that reached statistical significance in the 2026 analysis. Pan and colleagues screened 1,847 records down to 25 controlled studies published through December 2024, covering 1,876 participants, and reported pooled reductions in psychological stress (-0.71), depressive symptoms (-0.68) and anxiety symptoms (-0.77). For emotional outcomes they then ran a meta-regression with three predictors entered at once: sessions per week, the length of a single session in hours, and the total span of the programme in days. Only the total span came out significant, at about 0.024 of a standard deviation more effect for each additional day.

The same authors are careful about what that permits. Their model explained about 31 percent of the variation between studies, leaving two thirds unexplained, and they describe their own dose findings as tentative hints rather than firm prescriptions. The certainty of the pooled evidence is moderate for stress and low for depression and anxiety under the GRADE framework, heterogeneity exceeded 74 percent for every outcome, and a publication-bias correction shaved about 15 percent off the emotional-disorder estimate. The review was also never registered in advance, which the authors name as a limitation themselves.

One further detail from the same paper deserves more attention than it usually gets. When forest therapy was compared against an active urban control, meaning people who also went out and walked somewhere, the effect was smaller (-0.62) than when it was compared against sitting indoors or a waiting list (-0.81). That comparison did not reach significance and rested on few studies, so treat it as a direction rather than a finding. It is still the most honest thing in the paper: part of what gets measured as a forest effect may be the disadvantage of the thing it was measured against.

Nobody has measured how long one session lasts

Almost every study in the 2026 pooled analysis measured its participants immediately after the session ended and never again. The authors put it plainly: with virtually no follow-up data, there is no basis for claiming that the psychological benefits persist over weeks or months. That is a striking hole in a field that has been running field experiments since the 1980s, and it is the single most useful fact for anyone deciding how often to go.

Two exceptions are worth naming, and both are small. Song, Ikei and Miyazaki reported in 2017 that blood pressure reductions in office workers were still present some time after a forest therapy programme ended, which is a physiological measure rather than a psychological one. A 2025 Hong Kong pilot followed 55 of its 100 participants for two weeks after a single 30-minute guided walk and found improvements in distress, resilience and sleep quality still in place, with no control group to compare them against (Wong et al., 2025).

If you do not know how long a dose lasts, you re-dose on a schedule rather than waiting to feel it wear off. That is the practical consequence of the missing follow-up data, and it is also how the people who keep this up actually behave. The ones who come back to me have a slot in the week that belongs to the forest, not a plan to return when things get bad again.

For people already struggling, single visits showed no effect

A 2025 meta-analysis of 78 nature-exposure studies with 4,987 participants found that in adults with symptoms of mental illness, one-time nature exposure produced no significant effect, while repeated exposure did, from 120 minutes of accumulated time upward. Bettmann and colleagues separated single visits from interval visits deliberately, because the two had never been compared directly across the literature. In adults with a diagnosed mental illness the pattern differed: benefit rose with a single visit up to about 105 minutes, then flattened, and exposures of 960 minutes or more showed neither positive nor negative effect.

Read that one with its scope attached. Bettmann and colleagues pooled nature exposure broadly, not guided forest therapy, and their studies ran from 1990 to 2020 with clinical and symptomatic populations. It does not say that a first session is wasted, and I would not describe it that way to anyone who has just had one. What it does say is that among people carrying real distress, the measurable gains clustered in the repeated visits rather than the single ones.

The 2026 forest therapy analysis points the same way from a different angle: people who arrived with diagnosed stress-related conditions, burnout or high baseline distress improved more (-0.91) than healthy participants did (-0.58). More room to move is the obvious explanation, and the authors say so. For what those changes look like inside the body, nature and the nervous system goes through the physiology and its nulls.

How long should a single visit be?

Twenty minutes is the working floor. A meta-analysis of 21 blood-pressure studies with 2,270 participants found that forest sessions of at least about twenty minutes outperformed shorter ones on blood pressure and cortisol (Qiu et al., 2022). A separate experiment in which 36 city dwellers took a nature break of their own choosing three times a week for eight weeks found that the drop in cortisol per minute spent was at its most efficient somewhere between twenty and thirty minutes (Hunter, Gillespie and Chen, 2019). Below that, you are taking a break, which is worth doing and is a different thing.

A guided forest therapy session runs two to three hours, and that length is not an attempt to accumulate more minutes. The sequence needs the room: an opening body scan and sensory invitation, a slow walk of a few hundred metres, several invitations with circle sharing between them, and a tea ceremony at the end that marks the return to ordinary life. Compress that into forty minutes and the middle part, where people stop performing and start noticing, does not happen. What to expect at your first session describes the arc in order.

A rhythm that holds through a Slovenian year

Here is the rhythm I recommend, with the reasoning attached to each part. Twenty to thirty minutes in the nearest trees, three times a week, covers the two-hour threshold and sits in the efficient window for session length. One guided session every four to six weeks gives you the full sequence and, in practice, keeps the solo visits honest: people who go alone drift toward walking for exercise without noticing. A group forest bathing session with Forest Compass costs 35 euros and runs two and a half to three hours; an individual session is 50 euros.

The nearest trees matter more than the best ones. In Ljubljana that means Rožnik rising straight out of Tivoli park, or Golovec on the southeastern edge, both reachable without a car; elsewhere it means whatever patch sits within ten minutes of your door. A rhythm that requires planning a trip will survive about three weeks. Forests around Ljubljana lists the ones I use, with how to reach each.

Winter is where most rhythms break, and it is the season worth protecting. Slovenian forests between November and March are quieter, emptier and colder, and the research does not support skipping them: measured relaxation effects hold up in winter forests, even if the immune findings mostly come from the green season. Shorten the visits rather than dropping them. Fifteen minutes in a frozen beech wood in January is worth more to your year than a heroic three-hour walk you take in May to make up for it. Winter forest bathing covers the cold-weather evidence and the practical clothing question.

If a company is asking the question, the answer changes shape. One annual away day in a forest is a nice day out, and the dose evidence gives no reason to expect it to move anything measurable. A quarterly half-day with the same team, or a repeated programme, is closer to what the studies that shifted clinical measures actually ran: the urban forest therapy programme that eased depression from moderate to mild and improved sleep in patients with depression was six sessions, not one (Yeon et al., 2022). Team building in nature and our experiences page set out the formats and prices.

What I say when someone asks me at the end of a session

Pick a slot, not a target. People who leave a first session deciding to go twice a week usually manage it for a fortnight, and people who decide that Wednesday before work belongs to the trees are still doing it in March. The research on total programme length rather than session frequency says something similar in colder language: what accumulates is the number of weeks you keep going, not the intensity of any single week.

Forest therapy supports relaxation and wellbeing. It is not a replacement for medical or psychological care, and no frequency of visits makes it one. If you are in real difficulty, the forest belongs alongside proper treatment rather than instead of it, and the 2026 analysis is explicit that recommending forest therapy for chronic mental health conditions remains speculative without evidence that the benefits last.