To Kew to se what autumn fruit and colour has been spared by two weeks of cold and windy weather. Grey is the colour of the season – indoors as well as out, it seems. We see it in furnishings, in fashionable décor (Nina Campbell’s new book Interiors is full of grey, and so is our son’s new house.) Is grey the new cream?

And yesterday it was the theme in Kew Gardens, remaining leaves now only scattered patches of warmth. But what warmth! How is it that the yellows ands reds of autumn generate their own wattage? It feels (perhaps it is) lighter under a yellow sweet chestnut or an orange beech than under the open sky.. These were the trees providing the warmest patches; most of the maples were bare. I had to cross a lawn near the Palm House to identify a small tree that formed a neat tower of deep scarlet: Malus trilobata from the Eastern Med. One to note.

But the gardens were full of activity – and electricity. They were preparing for the Christmas illuminated trail, a mile of paths lit with every modern lighting trick; the first time Kew has opened at night in winter. (The show runs on certain days between November 28 and January 4; see the website). I remember when Westonbirt first did the same thing; it was an inspiring sight; trees make ideal subjects for theatrical lighting.

And hortiphones,,too: strange His Master’s Voice-style speakers scattered around ready to perform: music? Commentary? Mysterious vegetable sounds? I can’t wait.

Home from a wintry dash to Krakow and Beaune, two of Europe’s best-preserved ancient towns. Beaune still has its girdle of walls; at Krakow they pulled them down and replaced them with a green belt charmingly called the Planty (can it really mean just that?), now a circular park of mature oaks and limes and planes. Every town should have one.

Home to find the new greenhouse ready for commissioning. Gulp. The plants that go in here depend entirely on me for their survival. The bench is a blank sheet, a bare wall, a challenge. Happily the last panes of glass have gone in just as the temperature falls to zero; the first inhabitants are genuine refugees; a cymbidium, some favourite pelargoniums from Saling Hall, some salvias still in bloom.

The lemon pot is too heavy for me to move from the verandah; shall I be able to keep it snug enough tucked up in fleece, with a glass roof but no walls? Not I fear if this winter is like the last.

But a score of pots of bulbs – also refugees, this time from the squirrels that have already been munching – gives the bench a look of purpose and hope. Snowdrops are poking up; I shall see them this winter in a completely different focus from the white rugs of the countryside. Iris reticulata is stirring. Worryingly a cyclamen the size of a Chelsea bun is not.

How carelessly, casually, unthinkingly did I once chuck armfuls, wheelbarrow loads, whole branches on the bonfire. How slowly, thoughtfully, with what infinite pains did I spend this afternoon dissecting, dividing, dismembering my prunings with my secateurs to cram them into the council’s black plastic bags.

It is the difference between the country garden and the urban one. There are no big gestures in a garden shorter than a cricket pitch and no wider than a front parlour. Nor in a garden whose only outlet is the exiguous all-purpose corridor between the back stairs and the front door.

There are compensations, though. Town gardening, I’ve decided, is like putting on reading glasses. The foreground is enlarged, the distance blurred. But the object of your attention appears in such clarity of detail that it can occupy your mind like a whole landscape. Is this what William Blake meant when he saw ‘a world in a grain of sand’?

Today’s job was reducing a climbing hydrangea that was blocking the eastern light from the new verandah, the library and the kitchen. They are powerful climbers, equipped for tall trees and long branches, their brown wood stout and flexible, their foliage dense and their flower heads many, copious and intricate. Structurally they are composed of multiple right angles or near right angles, each ready to snag a plastic film. The only way to fill a bag with them is to chop them into little bits. By the end of three bags I know their anatomy intimately. Hydrangea petiolaris is more than a mere acquaintance now.

I look round the garden, the falling leaves, the growing climbers, the old growth to be cleared away – not to mention the tree to be pollarded – and see a future of black plastic bags stretching away to the distance like crows on a telephone wire.

I can think of a dozen reasons for visiting New York in October – the best month in this continent of extreme weather – but the one that comes uppermost in my mind is the Conservatory Garden in Central Park

I know I bang on about Central Park, probably once a year, but then it has qualities none of our London parks (I love them too) can match. Seemingly endless paths (trails sounds more American) among huge grey rocks like monster whales and enormous trees, across savannah, skirting lakes and ponds, leading to cafes, kiosks, the boathouse restaurant, the zoo, the auditorium…. and several gardens. The Conservatory Garden, the most accomplished, the most formal and the most complete in itself, is way up around 105th Street, almost in Harlem.

Its centre is an ‘Italian’ design – though it would be hard to find avenues of crab apples around a simple level lawn in Italy. The ‘English’ third is the most intimate, cloistered among yew hedges, sheltering a bronze of Mary and Dickon of The Secret Garden, reflected in a little waterlily pond.

The ‘French’ garden is the October event: an overwhelming display of Korean chrysanthemums, a bank fifteen feet wide right round a rectangular piazza, enclosing the city’s jolliest fountain; three mischievous and nubile young ladies dancing round the water.

The chrysanths were a gift to the city in 1947 as a war memorial. The donor was Mary Lasker from Chicago, a huge benefactor of medical research. They were originally grown from seed, a strain developed by the Park for decades, selecting a wonderful palette of brilliant colours, orange and violet, yellow and white, red and brown. Other gardens show them oriental-style, extravagantly coiffed into pompoms and cascades. Here they are grown as they would grow in some dream meadow, a random medley, not pinched and primped but tilting this way and that, jostling, playing like the dancers round the fountain.

These days I’m told they are grown from cuttings and planted out from 2,000 pots in late May. Not that they are tender, even in New York winters, but they replace the spring bedding of 20,000 tulips. They draw New Yorkers like a baseball game. I’d love to see a really full-throttle Mum Show in England.

The sun is low enough in the sky this afternoon to rub in just how little light our new garden will get in winter. There will be improvements: the overhead shade of the huge sycamore and big walnut is going to be massively reduced. But this is looking forward several seasons. Half the garden will see no direct sunlight all winter.

I am turning over various possibilities in my mind. Portugal laurel, ivy, aucubas and some snazzy box topiary were our predecessors’ solutions. But I crave a smooth restful green patch; the equivalent of a lawn, which would never thrive here. Is a moss lawn a practical possibility, I wonder? I dream of the green tranquillity of the moss gardens of Japan. But does it need the warm wet climate of Kyoto?

Look up ‘moss lawn’ on the internet and every reference is about getting rid of moss as a nuisance. The only pro-moss site I can find is Gardens Inspired, from somewhere unspecified in the (I suspect southern ) States. Debra Anchors gives recipes for planting a moss lawn: literally recipes; they involve scraps of moss collected from nearby put in a blender with either yoghurt or beer, then sprayed on to bare ground and watered until it goes green. I love the idea. Worth an experiment, surely? I’ve heard it said, too, that regular spraying with Round-up can encourage it .

Alternatively, if I do nothing, our current modest crop of mind-your-own-business, the pretty little Helxine (or Soleirolia) soleirolii, will pretty soon do the business for us. Its tiny bright green leaves are the terrestrial equivalent of duckweed. They say it is almost equally pernicious, delicious though it looks in the interstices of old greenhouses.

Now that the squirrels have almost finished chewing the walnuts on our neighbour’s tree and dropping the remains on our garden they are starting on our pots of bulbs. I have been planting pots in anticipation of the greenhouse we are excitedly expecting in a week or two, using what is left of our collection of wonky old handmade ones. (I scan old garden sheds, greenhouses and shops selling bric a brac wherever I go, hoping to find these increasingly rare veterans).

Narcissus seem to be the squirrels’ first choice, with Iris reticulata also popular and snowdrops an acceptable snack. Do tulip bulbs have less scent, or is it because I plant them deeper that they have (so far) been relatively unscathed?

The brick base of the greenhouse is all ready, a (very) minor masterpiece in reclaimed London stock bricks in their characteristic medley of gentle colours: yellow, pink and grey. It is already hard to distinguish from the surrounding garden walls. The bricklayer who built it is from Croatia; a gentle smiling man with not much English. When I told him how I intended to fill it with flowers he said “I like this job. I like flowers very much. At home I have flowers everywhere; in the hall, in the kitchen, on the walls. People say I am like woman’.

Where is this, and what is it called?

The Royal Parks are so important to life in London, indeed to the whole identity of the city, that I feel ashamed I knew so little about them; how big they are, how many, and how they are run. Linda Lennon, the Chief Executive responsible for them, came to the AGM of the Metropolitan Public Gardens Association the other day (I am the current president) to enlighten us. Let me pass on some of what we learned.

The total area of the parks is 5, 000 acres, of which Richmond Park represents a half and Bushy Park another 1,100 acres. There are eight in all, and seven other non-royal green spaces (Brompton Cemetery is one) run in conjunction with them. They claim 40 million visitors a year – surely a huge under-estimate (though are you a visitor if you simply walk through on the way to your bus?)

They estimate there are 135, 000 trees, of 250 species. Again, how do they count them, and how big to they have to be to qualify? The parks encompass 15 miles of river and contain 280 statues. Regent’s Park and Primrose Hill taken together are the biggest in central London, covering 395 acres (of which 100 are dedicated to sports). Hyde Park covers 350 acres and Kensington Gardens 242 – so taken together they far outweigh the Regent’s Park area. St James’s Park covers 93 acres – but this includes the Mall and Horse Guards Parade. The Green Park, the most perfect and consistent in character (but this is only my opinion) is a mere 53 acres.

All of them together cost £32 million a year to maintain, of which the government pays £18 million – and going down. They employ (a mere) 110 staff, and gave up having their own propagation and production departments in the early ’90s, to the delight of the Dutch nursery business. It is hardly surprising that pop concerts and other crowd-pullers are put on more and more often. Linda told us that this year’s noise-reduction at a big bash produced an unexpected result: complaints from people living nearby who had invited their friends for the evening that they couldn’t hear the music properly any more.

The deer are nibbling the grass just outside the window as I write. Two does and a faun that can’t be more than a few days old. Four more, with one buck, are showing their white backsides as they graze the meadow a hundred yards off. They don’t know it, but they’ve just won an argument. The broad meadow below the house, 18 acres dipping down to the Lymington River, will be theirs. Their private park. My foolish idea of a landscaped arboretum goes in the bin.

Young trees and deer don’t mix. I learned the lesson the hard way in France years ago, when my landscaping ambitions were foiled again and again by game of various kinds.

Red deer are more formidable than roe deer, and boar worse than either to a tree- planter and dabbler in streams and ponds. At Saling Hall we had a few visitors, and far worse, muntjac, but managed to handle them on our 12 acres. Here in the New Forest there seems no point. Indeed the deer are the point – originally of the whole forest.

And would a meadow dotted with new trees, however interesting or rare or fiery in autumn, really be more beautiful than a little green park with deer and the few scattered old oaks we have here? Certainly not so appropriate. We (that is our daughter’s family) have a splendid piece of old oak woodland above the meadow. Gentle thinning of the big trees (and clearing of ponticum) will give us forest fringes to adorn with a few new trees I will have to choose with maximum deliberation and protect with scrupulous care. And I shall have much more time to enjoy the wild life.