It has rained every day so far this year in North Wales – a state of affairs more unusual than you might think. The waterfalls are in splendid spate; just now we saw a group of daredevils canoeing down a fearsome sheer drop, free-falling through the spray. Our little river is in that sinister mood when it runs swift and silent, no ripples breaking its swirling surface. And the ground is saturated. I made the mistake of stepping off a hard track to skirt a fallen tree and went in to the top of one welly. Luckily not over the top, or I would have had to abandon it and limp back barefoot, the light quickly fading, half a mile downhill to the car – not a prospect to relish.

Worse, I was effectively lost. We have just clear-felled the spruce and larch on a wide stretch of hillside, and with the trees has gone all my sense of place. I was negotiating what had been a favourite bit of track, where tall trunks framed the first silver glimpses of the sea. Ferns were thick along the path, giving way to deep green moss and gleaming threads of water under the dark rows of trees. The track turned left here by a flat grey rock to skirt the steepest slope. There was no rock, and no track; just stumps and ruts and snaggy branches higgledy- piggledy everywhere. Getting back down in the dusk was tricky.

Forestry is a messy business; for long years calm, verdant, woken only by the flitting of birds; then suddenly the Somme. The place you knew and loved has ceased to exist. At least I am responsible, or at least obediently following the cycle of planting and harvesting. Foresters are to blame for the biggest changes anyone can perpetrate on the landscape, eliminating beautiful familiar places at a stroke.

So what is a “place”? How is it different from a map reference? A place has intelligence; it depends on understanding – of its purpose, its history, of the forces that flow through it. A landscape or garden designer’s job, or one of them, is to show you where to cast your eyes, and where to put your feet. There are forces at play in a design: sight-lines and pathways and the interplay between them. They are different in different seasons; winter transparency and summer solidity; the sun lower or higher in the sky; pale shadows and black obliterating ones. Colours, of course, and textures, eye-catchers and passages of restful green or grey.

All these contribute to a sense of place. They give you confidence, explain, perhaps subconsciously, where you are and why, what the gardener wants you to observe and enjoy, where you should go next to be excited or to be soothed into a reverie.

A resourceful gardener controls your mood; invites you to share his own, then changes it. It is the reason for the overwhelming success of garden rooms, of Hidcote and Sissinghurst and their many imitators. Great gardeners do it by suggestion, by modulating scale and colour, enclosing you or letting your eyes roam free, splashing water about or letting it reflect the sky: there are a thousand ways.

The forest will grow again – but it will be a different place.

There’s a limit to what the council will let you do to your trees in a leafy borough like this one. It has absolute power over the woody leafage. Not the power to plant a tree in your garden, of course, but the power to stop you disposing of it as you see fit. I am stuck, then, with a disproportionate amount of sycamore. I have reservations? A lack of proper respect? My problem: I bought the tree with the house.

In this privileged area, though, even the tree surgeons are a cut above the norms. I googled “Tree surgeons, Kensington” and stopped at the second name. Not a name to forget easily: Fergus Kinmonth – and one I recognised as a member of the International Dendrology Society and a visitor to our Essex garden. How many dendrologists climb trees with chainsaws? Probably not enough.

Fergus came round and we talked about the two trees that last summer kept the sun from touching our garden, the sycamore and the neighbour’s walnut. I know they get more than their share of publicity in this diary. But then they take more than their share of a diarist’s light.

Tooth-sucking from both of us. “They’ll let you take off the same as last time”, said Fergus. “That’s just the tips,” said I. “Precisely. This is a conservation area.” “So what is it they’re conserving?” “People don’t like it when the greenery they see from their windows is removed.”

I’m not keen, either, I admit. But here we have the politician’s dilemma. “If we want things to stay as they are, things will have to change” is not a message that public servants want to hear. So no radical tree surgery; just a snip here and there while the problem grows. Fergus and his team came and snipped – very handsomely and tidily, I must say. Not a twig is left: just a massive black tree-skeleton in the sky, ready to do the same again, plus a little bit – to need painful surgery again in a year or two.

Woke in the night with the scent of a pot of Iris danfordiae filling the bedroom. I have never grown this tiny turk before and was unprepared for its perfume. What insects are such flowers of the winter trying to attract? There are not many, and their scents, it seems to me, have something in common: a trace of honey and a musky facet which can become a little too strong at close quarters. Winter Heliotrope and Viburnum Bodnantense are both better at a little distance. There are wines that do this to me; Muller Thurgau, for instance.

When flowers use their energy to broadcast scent at night can it be moths they are after? Certainly they look eager for visitors; the little yellow irises stand bolt upright like nestlings with their beaks stretched open, beseeching food.

What is a dilettante? Someone to be admired, scorned or pitied? Would you admit to, or maybe claim, the title?

We had a lively debate about it the other night, one friend taking the fashionable view that it means uncommitted, non-serious, even amateur (and is therefore to be condemned). My view is pretty much the opposite: that it infers commitment of another sort, passionate interest rather than professional duty.

It depends on the context, of course: in medical matters we hope for certainty and rely on the apparatus of peer-reviewing. An amateur surgeon would not find many customers. In a different field, (planning matters concerning historic buildings are on my mind at present) the common sense and taste that an experienced dilettante can bring can be far more valuable than the callow judgements of a professional planner.

It is not uncommon for the long-brewed plans of an owner and his architect, arrived at after years of study of a site, its surroundings, its history and natural conditions, to be rejected – or certainly (almost inevitably) modified – by an individual who has no background knowledge of the matter. “I would prefer the door to be here”, or the window to be a casement, or a wall to be lower or higher, is a common, and completely outrageous, statement.

Outrageous because this individual’s opinion automatically acquires the authority of law. I don’t recommend questioning the qualifications, the judgement or even the bona fides of a planning officer. Seduction is more likely to produce the required result.

So yes, I am happy to call myself a dilettante – a word that means simply one who delights. A set of young aristocrats who made the Grand Tour in the mid 18th century (and were probably all at Eton together) met as a club under the name of the Dilettantes. Their inaugural meeting was painted by one of their members, Sir Joshua Reynolds. There are clubs and groups with similar leanings today, but who claims the delightful name?

And there’s another calling that has lost its meaning nowadays: that of the flâneur. A flâneur is one who strolls without intent – except to observe the world. Cornelia Otis Skinner, the author Our Hearts were Young and Gay, defined a flâneur as a ‘deliberately aimless pedestrian, without obligations or sense of urgency, who being French and therefore frugal, wastes nothing, including his time, which he spends with the leisurely discrimination of a gourmet..’ The critic Charles Sainte Beuve called flânerie ‘the very opposite of doing nothing” ; Baudelaire called him ‘the botanist of the sidewalk’.

Need flânerie be limited to sidewalks, though – let alone to the French? How else to describe what I do in someone else’s garden?

To Exbury the morning after the pre-Christmas storm. Remarkably little damage: almost none to the high oaks that provide the principle cover – or any of the deciduous trees. Cedars with their heavy rigid branches and Scots pines with their sinuous ones are always the main casualties. But below them, washed and polished by the rain, the rhododendrons and camellias and all the other evergreens gleamed in the sun with a thrilling look of promise.

It must surely be an illusion that immediately after the shortest day plants take on an attitude, or at least an appearance, of expectation and hope. I know primroses do: their leaves prick up with just one extra minute of daylight. The buds of rhododendrons seem especially alert this morning. Excited and exciting, in fact.

It is sad to contrast this thriving Rothschild garden with the family’s former estate in the western suburbs of London at Gunnersbury. Once Gunnersbury was almost as big and almost as horticulturally exceptional as Exbury is today. Its place in history reflected the

Rothschild fortune: Disraeli was an habitué; it is where Britain bought the Suez Canal. It is still in existence, but the only reminder is the anonymous green backdrop to a row of post-modern office blocks along the Great West Road flyover where it crosses the NorthCircular Road. Gunnersbury was one of the group of great houses that graced the approach to London from the west, or down the Thames: Chiswick, Kew, Syon, Osterley, Marble Hill, Strawberry Hill, Ham and further upstream Hampton Court.

The creator of Exbury, Lionel de Rothschild, was brought up at Gunnersbury, but when his father Leopold died his mother sold the estate to the local councils of Acton and Ealing (at a fraction of its potential value) to remain as pleasure grounds in perpetuity.

Sadly the ratepayers have seen it more as a burden than an asset. Some said that the other historic parks were plenty; no need for another. The grounds at Gunnersbury are merely maintained, the houses (there are two) in disrepair, the remaining great trees rotting and tottering. Today it has more archaeological than horticultural allure.

But there is hope. The two boroughs (now Ealing and Hounslow) have a plan for restoration and future use of the house (now a modest museum) and the grounds, are consulting the public and have appealed for Lottery grants of £17 million. It will be too late, alas, for the garden to recover its old importance. But I shall go in the spring to see the buds begin to swell.

There were reputedly nine hours of daylight today, the shortest day of the year. It didn’t feel like it. We opened the curtains on a pale-looking night lit by streetlamps and closed them again a good hour before tea. I was out, or at my desk, for the admittedly bright and breezy middle of the day; not, in other words, able or in the frame of mind to contemplate the garden. I did spend a happy half-hour absorbed in the greenhouse, swept leaves and tied up a climbing rose. The thrill of the day was finding a remarkably precocious camellia, just one pale pink, complex and rose-like flower, on the old bush we inherited with the garden. A sasanqua, I wondered, flowering before Christmas? No, I think, just an impatient japonica – rewarded for its haste by pride of place on the kitchen table.

But I love contemplating; spending quiet quarter-hours with only my eyes engaged. Last thing at night (especially after good wine) I can gaze into the fire for an hour on end – even at the repetitive flames of

our faux-coal gas fire. In our country garden it was a family joke how father dawdled away the dusk until on a dark night he had to grope his way indoors.

The garden is a different place at night, and with nights as long as they are in mid-winter it is a place to explore. There are certainly lights to be seen: the yellow rectangles of neighbours’ windows, the bright pricking of a plane (or is it a satellite?), the moon intermittent through gauzy clouds, the reflection of a street light off a wall, the red light on the tip of a towering crane three streets away in Holland Park. They make a picture of sorts, eye-catchers in the black landscape of bare branches and gables against the sky, the backdrop to the dark foreground of plants and structures I know so well but can’t see.

I switch on the garden lights and the deliberate theatricality comes as a shock. We inherited the lights, too, from our American predecessors in the house. They shine downwards from higher or lower on the walls, a dozen of them, throwing little pools of light, some of them half-obscured by evergreens, on the paths and steps. I have moved one to spotlight the monumental (or so it appears at night) trunk of our centenarian sycamore. They could be better planned, be changed to LED, and no doubt in expert hands make the garden look almost glamorous. But I think I’d rather have something more mysterious to contemplate.

Thinking about the rocks in Japanese gardens led me into a reverie about autumn in Japan; a wave of homesickness for the cool damp and bright light of short days among the orderly fantasies of Kyoto or Nara. At just this moment a faithful correspondent wrote to paint a picture of a garden I have never seen, to remind me, she said, of Saling Hall.

In that marvellous gardening climate autumn runs late. Early December and the picture is still full of bright colour, ‘with Sasanquas bursting in bloom wherever one goes, autumnal cherry blossoms, the red fruit of Ilex rotunda, Ilex serrata and of course Nandina domestica, Idesia polycarpa high above and Sarcandra glabra and Ardisia crenata below, pinkish Euonymus sieboldianus, even purple beads of Callicarpa japonica, bright Kaki fruit, and besides the maples there are the reds of Enkianthus perulatus, Rhus sylvestris and golden Ginkgos, masses of freeform mums delightful around potagers, probably planted to have ample flowers for the family altar at this time of year. There is also the lovely fragrance of Osmanthus heterophyllus’.

Of course it is not our climate. Kyoto lies on about the latitude of Tangier. On the other hand the Asian landmass to the north ensures colder winters than anything in Africa. There is often snow, and sometimes frost, from January to early March. Average humidity is as high (and rainfall over the year about the same) as in North Wales, with June the wettest month and December to February driest.

The summer heat would not suit me, but for most of the year it would be a wonderful place to garden. The problem, as anyone who has been to Kyoto will tell you, is the crowds. It is nigh impossible to see any of the famous gardens without a crowd – often a uniformed school crocodile – blocking the iconic views. My friend’s pictures show empty gardens, either through cunning timing or because their subjects, north of Kyoto in Shiga prefecture round Lake Biwa, have not yet been added to the tourist circuit.

It is typical of our national taste in gardening that a rockery is a place to grow plants we categorise as suitable and appropriate – rather than a place to admire rocks. Rock-worship is something bizarre and eccentric indulged in by the Chinese (craggy rocks, usually on end) and the Japanese (smooth rocks, often lying down), while we pursue our obsession with flowers and leaves.

Tell English gardeners that a warlord of a thousand years ago took the garden rocks of his defeated rival as trophies, transporting them to his own garden miles away, and they will roll their eyes. “And pine trees” you add, and faint comprehension dawns. Trees are plants. Excessive, perhaps, and impractical, but moving plants, even as booty, is something we understand. When we incorporate stone in our gardens, and not as a support for “alpine” plants, we cut and dress it into architectural forms.

We do recognise menhirs. A fine standing stone has a place in our culture. One of the finest (I claim, with no modesty at all) is the rock I carried from North Wales to our old garden at Saling Hall. In its height (nearly 9 feet), its texture (grey granite patterned with lichens that vary from light green to dull orange with the seasons), the frozen flow of its formation and the cragginess of its top, like a distant summit, it draws visitors like a splendid sculpture – and stays indelibly in my mind.

These lapidary reflections were brought on by a new issue of SiteLines dedicated to stones. SiteLines is the (suitably landscape format) magazine of the Institute for Landscape Studies, a brainchild of Betsy Barlow Rogers, the remarkable New Yorker responsible for the renaissance of Central Park.

No city is stonier than New York – which is why it grows skyscrapers with minimum fuss. The defining features of Central Park are the grey rock outcrops and glacial boulders revealed (not without effort and expense) by removing thousands of tons of soil and glacial alluvium to show Manhattan’s bones. Olmsted’s “lithic mood” coincided with his discovery of Yosemite and the dramatic geology of the Sierras. My own lithic mood is longstanding, currently latent, but stirred by the thoughts in this most original magazine. (www.foundationforlandscapestudies.org)