The custodians of England’s forests have launched a drive to encourage more people to make regular visits to woodland to improve mental wellbeing.

They claim that research shows that two or three short jaunts to woods and forests dramatically improve mental as well as physical health.

Forestry England, a division of the Forestry Commission, says more than half of the population of England lives within six miles of one of its sites and claims almost everyone would benefit from spending more time among trees.

It is keen to dispel the notion that woodlands are dark, scary places by making more of its sites easily accessible, and is organising events working with vulnerable people or those who feel cut off from the natural environment, to draw more visitors in.

As part of Mental Health Awareness Week, Forestry England is working with the television presenter and tree fan Kate Humble, who has described how she often finds comfort in sylvan settings.

She said: “We all have moments of anxiety or stress or confusion or sadness. Sometimes it can be really hard to articulate that to another person. You can talk to a tree: they feel old and wise and at times you need an old and wise thing that isn’t going to judge you.”

Humble said she had a particular 600-year-old tree she turned to, named Old Man Oak. “He is so stately. There have been many occasions when I have gone and sought the solace of Old Man Oak. We live this very ephemeral life. There is something about the solidity of a tree that can give you a sense of security.”

Humble also said she thought it was fine to sometimes feel a little nervous in woodland. “It’s a lovely feeling to almost be lost, but not quite, and to feel you are being led down mysterious paths.”

Forestry England has gathered data from a string of studies that it says shows there is strong scientific evidence that visiting a forest can improve mood and attention span, and even enhance psychological stress recovery.

It says walking among trees reduces levels of cortisol, a hormone associated with stress, and claims a forest walk can boost the immune system through breathing in phytoncides, which trees emit to protect themselves from germs and insects.

Bianca Ambrose-Oji, a senior social scientist at Forest Research, also a division of the Forestry Commission, said the feeling of “total immersion” that was possible in woodland made it such a positive place to be. “It’s a good way of getting out of a routine,” she said.

The science is not completely clear, however. The European body Forest Europe agrees there is a lot of evidence that forests boost mental health wellbeing.

But it also says: “To summarise, we can say that the evidence on the effect of forests on psychological health is not yet good enough to say when, where, and for whom given effects will occur or how long they will last. Positive effects may not be experienced equally by different groups of people and not all types and sizes of forests might be equally effective.”

The drive to encourage people to visit woodlands is part of the Forestry Commission’s centenary celebrations, which also includes the largest ever survey of forest wildlife, new works by sculptor Rachel Whiteread and former poet laureate Carol Ann Duffy, a show garden at the RHS Chelsea Flower Show and the planting of commemorative tree avenues.