So - this is NOT about hedgehogs! But it is about the wonderful world of nature which we share with hedgehogs … so, there is a link! And also, this piece is a taster … I write a monthly column for Scribehound Gardening, alongside some real gardening experts and commentators like Alan Titchmarsh. This is behind a paywall, however, they are doing an offer - you can have a month for £0 … and decide whether it is for you! Here is my most recent offering!

I have always been led by my nose. Somewhere underneath the more obvious Hobbit, there is an enthusiastic dog, I reckon … no, I am not quite to the point of being busy checking ‘wee-mail’ beside my real dog in the park, but still - when there is something that might smell interesting, I am straight in there - the incident with the otter poo is a case in point, but that can be for another time!

When I first met my biological mother, just over 20 years ago, this was something we found very much in common. As we walked around her immaculately vibrant and wild garden near Birkenhead, the plants were described as much by their scent as their size or colour. We both get most excited by her sweet peas - even as I write that, I get something of their smell triggered in my memory.

My garden has, over the years, and through benign neglect, developed a patio-covering wisteria. It is the most precious plant in my garden and whatever I am doing to it (or rather not doing to it) works, so I just let it get on with doing what it does best. And that is, make my heart sing. The late April rush of sherbet, honeysuckle and fresh hyacinths - oh, I need a sommelier’s thesaurus to help me with this - I am sometimes moved to tears by the early season hit of scent.

It has got to the point that I resent having to be away from the garden during the peak wisteria time. I spend hours out there, photographing the pea-flower petals and just letting the sweet scent of hope and summer flood my senses.

Some years, the blossom has been so intense and dense that friends have invited themselves around to pose for photographs! But I note that while they are thrilled by the cascades of pinks and purples, they are not as enthusiastic about the smell as I am. I guess my mother and I are wired a bit differently! Who else is led by their nose through a garden?

Archie, one of my son’s fellow choristers, when he was singing for Magdalen College, Oxford, had a nose like that - and there was something special about seeing a child working his way around the manicured quad, being as thrilled by roses as I was.

My excitement exceeds that of most of my friends - so is the scent of a garden just a ‘nice to have’? Or is it more than that?

In her recent book, Good Nature, The New Science of How Nature Improves Our Health, Kathy Willis, Professor of Biodiversity at the University of Oxford, and now Crossbench Peer, takes a deep dive into what is actually going on when we indulge in a scensual walk among the plants!

There is plenty of strong scientific evidence that there is a very positive psychological and physiological response to time spent among the green - and also that the sounds of nature stimulate good reactions too. Shinrin-yoku is the Japanese practice of ‘wood-air bathing’. While it might sound like some ancient tradition, it was actually an invention of the 1980s, to advertise Japan’s forests as a place of healing when experienced through all our senses. At the time, there was no scientific evidence that it worked … there is now!

Scent operates on a different level as well as the aesthetic - there are a host of volatile chemicals that leap from flower and leaf into our heads. Depending on the plant, the reaction can be anything from gagging to glee (whoever chose to plant female ginkgos in the park behind my home had a very dark sense of humour!)

Kathy makes the very interesting observation that, unlike sight or sound, scents are systemic - they act on the body as the stimulants are breathed into our lungs and then cavort their way through our blood, triggering reactions from the nervous and endocrine systems.

Research into around 90 different plant families revealed over 1,700 volatile organic compounds - which is why we are blessed with such an array of scents. For example, freshly cut lawn is made up of simple alcohols and aldehydes. More complex smells come from longer chains of carbon atoms. The terpene, linalool, gives us a strong, sweet ‘flowery’ scent, lavender comes from linalyl acetate. More predictable are pinene and limonene (I won’t be awarding prizes for guessing what they smell like!)

Kathy wanted to see whether there was more than just a psychological reaction to time in the scensual company - this is important as there is now a move towards social prescribing - which often involves getting people out into nature. Could we start to see prescriptions for plant-sniffing?

While research into the impact of scent chemicals on our bodies lags well behind work on other senses, there is now clear evidence that smelling the right plants can, as she says, ‘not only reduce anxiety and levels of stress, but also inflammatory responses, and enhance our immune systems through the elevation of natural killer cells in our blood’.

This is not the sort of bland platitude found in the advertisements of snake-oil salesmen, but the result of an awful lot of serious research published in peer-reviewed journals. One study looked at the impact of scent on drivers … both rose and peppermint generated better driving.

‘Smelling the scent of fresh roses, even for just 90 seconds, has a positive impact on physiological and psychological indicators of stress in our bodies.’ How about that - you are growing a pharmacy in your gardens!

So when you find yourself nose-deep in a rose, or giving the leaves of a lavender a loving squeeze, you are indulging in a health-promoting regime! I am very happy to self-medicate in park and garden! What are your favourite medicines?