However much I look forward to a visit to our Welsh woods I am still amazed by the way they lift my spirits. What can I compare it to? A moment in music when you can’t contain your urge to sing. Finding a fresh breeze on the beam that fills your sails and starts the water running noisily past. A first sip of champagne, indeed.

Entering the woods, feeling the powerful presence of the trees, breathing their unameable smell, tracing in the seeming chaos of leaves the unalterable patterns of each tree’s growth, the cool of their shade, the brilliance of their green, I am lifted onto another level of living and forget everything else. I become a forest creature.

Each time I visit a plot we have planted in the past fifteen years or so I am shocked by the extent of new growth. We were here in June, when new shoots were just sketches of the picture to come. Three months later two dimensions have become three, every tree has added maybe five per cent to its height, but ten per cent to its volume. The same space is even more overflowing with life.

A forest without paths is like a room without doors. Opening tracks and keeping them open is a forester’s first concern. Brambles, bracken, gorse and birch saplings block your way it seems almost overnight. One of the great joys is carving a clearing to let yourself in. It’s wonderful what a neighbour’s big tractor will do.

And an excursion from this demi-paradise? To a true fantasty just up the road, the ‘Italian’ seaside village of Portmeirion, a celtic Portofino with an impish sense of humour. Clough Williams-Ellis turned his romantic imaginings into reality here in this heavenly setting in the fifty years betwee the 1920s and ‘70s. Walt Disney must be mad with envy. Around his crazily eclectic all-sorts of campaniles and Cornish cottages, memories of Portugal and Wales and heaven knows where, C W-E planted every plant that loves mild seaside air, a whole wood full of wonders, and hydrangeas in thousands.

I come home to our workaday woods with my head full of plans that will come to nothing. Of a little New Zealand or a Sintra, a Santa Barbara indeed of exotic shrubs and flowers. Sheer folly. Nothing could be lovelier than the forest around me.

There are colours in fading hydrangeas that give me a little shock of pleasure every summer. The showiest of late summer flowers clearly have pigment problems; acid soil sends them one way, limey soil in the opposite direction. But all their pigmentation seems unstable. They can start out white and turn pink, or pink and go red, or blue and turn mauve or purple, And as they fade, in many cases, their pigment can disappear altogether, leaving a pale parchmenty ghost.

The pigments involved are the usual suspects: anthocyanins of various hues. The hydrangea’s chromatic weakness – which I rather see as a strength – is that its sepals (petals to me, but Trad is a stickler for scientific accuracy) only have pigment in one layer of cells. When they fade, that’s it. But what images their washed colours evoke. The paint on beach huts untouched for years in all weathers, tiny babies’ wrappings, dowagers’ shawls…..

How utterly different from their contemporaries the salvias. Salvias do primary colours. Is there anything redder than S elegans or splendens, or bluer than S. patens? There is a good buttery yellow in S. madrensis, and lots of subtle shading in between. S. leucantha encroaches on hydrangea territory, and S turkestanica is pretty ambivalent. As the hydrangeas fade the central American salvias get in to their stride. The one I wait most eagerly to see is van Houttei, part dusky scarlet, part maroon – and in flower for months on end.

It was the nursery that clinched it. We were house-hunting in London in March, in the dreary grey weeks when the East wind blew unrelenting day after day. One house had ticked the boxes, only to be taken off the market; others were laughably unsuitable in various ways. One icy day we visited a house in a street we didn’t know at all, to be welcomed into warm, well-lit, totally comfortable surroundings, decorated (said my wife) rather like an old-fashioned luxury hotel. Yes, I said, we could live here without even talking to a builder – though a chat with a decorator would be good. ‘It’s not really us’ said Judy.

Next day she went back on her own to case the unfamiliar neighbourhood. Yes, there were cafes, cleaners, a Waitrose, delis – and just across the main road, only 100 yards from the front door of the house under discussion, a flower shop occupying the ground floor of a rambling old house. Inside, the scent of flowers was intoxicating. It was instant spring – and led, through the back door, into an Aladdin’s garden, wintry though it was, of potted plants, potted trees, potted shrubs…an entire nursery. Narrow paths under tall planes lead the length of a film-set Georgian square – all nursery. She had found Rassell’s. We bought the house.

Rassell’s nursery, in Earls Court Road, goes back to the days when the road was a country lane leading to Holland House through Lord Kensington’s farmland. His lordship, apparently, started to lease his fields to developers to pay his gambling debts (this was the early 19th century). His old lodge house on Earls’ Court Lane he leased to a nurseryman, and in 1870 Henry Rassell from Sussex came on the scene. In 1897 he acquired the freehold of Pembroke Square (everyone else had to make do with a lease), opened his florist’s shop, and started the business which is still there. I pop in for something almost every day – if only for the sight and smell of hundreds of happy plants.

This is the rose pergola we are putting up in the Fellows Garden of King’s College, Cambridge in memory of my father, Guy, who went up to to King’s as an undergraduate one hundred years ago, survived four years at the Front, and returned in 1919 to finish his law degree.

In the autumn we will be planting the roses. If you have good experiences of varieties for pergolas, (the soil is light, the climate dry) do please share them.

We’re just back from a seaside holiday, this year perfectly timed for two weeks of perfect summer, when simmering in London is not the connoisseur’s choice.

The temperature on the Solent, with a steady westerly breeze over Christchurch Bay, was five Celsius degrees lower than on the commons of the New Forest five miles inland. I am discovering the pleasures of a seaside garden – not, I’m glad to say, one totally exposed to wind and spray on a beach, but walled and sheltered by the little house, with the sea over the saltmarshes at high tide only sixty yards away. The air is heady with the scents of seaweed and saltgrass and tidal mud, and luminous with ocean light.

There is such a rewarding template for seaside gardening that there seems no point in being original. What’s wrong with hydrangeas and montbretia, and fuchsias and thrift? But drought can be a serious worry; the soil is basically sand and gravel and shingle and rain often seems to skip the beach to fall inland.

When we arrived I had the deep joy of watering a parched garden. I turned the rusty tap on the water butt and heard the jangling of stored life and energy that had only been breeding mosquitos as it filled my can. As I watered I was cutting down the top hamper of everything that had flowered and withered. Water and fertilizer would bring a second flowering – of some things. Or at least a fresh covering of leaves.

The garden is about 40 feet square, two-thirds paved, more dedicated to sunbathing and guzzling seafood than to horticulture. It has a campsis-choked pergola but otherwise no shade; apart from one raised bed the planting has almost all been low-growing. The house wall supports a climbing hydrangea; there are capabilities here.

At first I thought of a tree, maybe a pine, in the central brick-edged bed. Then I remembered a plant I was given by Cedric Morris in Suffolk many years ago; almost the only woody plant, as I remember, in his great open iris beds, a shrub growing perhaps seven feet high with a propensity to sucker – could this be why he gave it away so freely? It is Elaeagnus commutata or silverberry, a North American native used for its nitrogen-fixing abilities in dreadful soil.

In the narrow garden facing the sea, between house and road, I have planted agapanthus and Hydrangea quercifolia – a favourite in my daughter’s Riviera garden where it grows huge, flowers wonderfully and colours like a furnace in autumn. I don’t expect such a performance in Hampshire. It drank the water from the butt like a desert traveller, though.

The question becomes acute in summer: which would you rather have, a sunny garden or a shady one?

The majority view is understandably for sun. “South-facing garden” is a selling point. In town gardens you may have no choice. Our house is on the north side of an east-west street, the right house but the wrong garden? We had our doubts, but not any more – at least in summer, when it matters most. The summer sun starts the day peering over the eastern wall and finishes it beaming over the western one. The garden side of the house stays cool and the garden gets plenty of light. We are also blessed to have a tall tree in our neighbour’s garden to the west. We have dappled light on a sunny day in the centre of the garden.

Unfortunately the tree is a walnut, a beautiful dome of leaves on a smart grey trunk, but a hailstorm of green nuts in early summer and a constant rain of half-chewed half-ripe ones when the squirrels move in (they’re never far away).

As to plants in the shade, our predecessors took the view that box was the only thing. We are trying everything my favourite advisor, dear old Brigadier Lucas Phillips, advises. His Modern Flower Garden is never far from the top of my book heap despite being 45 years old.

The hydrangeas are just coming on, the blue ones from Saling that I christened Len Ratcliff after our benefactor have pride of place.: four big pots around the central (to use a grand term) piazza where we sit. The Brig says all campanulas tolerate shade. My favourite C. persicifolia certainly does. The pelargoniums in pots need promoting to the sunniest part at the far end. The roses on the walls (I don’t know all their names yet, but I know I don’t like Fragrant Cloud) are doing fine – high up above the wall. The scarlet Fuchsia boliviana, a standard in a pot, has been brilliant. Runner beans have been a disaster; being late I bought plants and failed to read the word dwarf (in dwarf type) on the label. So my poles are bare, with a few ludicrous plants at the bottom. What, I ask, is the point of a dwarf runner bean when the whole point is their climbing?

We’re experimenting with agapanthus. The plants we ordered at Chelsea have just arrived, with one flower bud each, seriously pot-bound. They’ve gone into deep gravel and old manure watered every night until they get going. Not everything is perfect. We don’t like a couple of the established roses (Fragrant Cloud is one); but how do you change them? Could one cut them down and bud onto the base? A Fuchsia magellanica has some lurgy that eats away its lower leaves, turning them brown – so presumably not a slug. There are lots of snails, but also the friendliest blackbirds and robin. Yes, on balance the shady life is a sweet one.

….. that was the title Tom Stuart-Smith gave to a Literary Festival organised by The Garden Museum in the Stuart-Smith’s garden last weekend.

The timing was propitious: only the second weekend this year when a festival in a garden had no need for umbrellas. Saturday was warm and partly sunny, Sunday was a proper summer day. We needed the shade of the tent for the lectures that were the centrepiece; a tent you discovered within beech hedges in the heart of a garden as lovely, and in as beautifully-timed perfection, as I could imagine. So beautifully-timed, in fact, that groups of flowers that had been in promisingly imminent bud on the first day showed their colours to the sun on the second.

The garden crests a modest ridge in a corner of Hertfordshire miraculously preserved from new towns and motorways, sheltering among its high hedges, then suddenly bursting out into a long view over fields and woods. There are few gardens these days where perennials hold sway: here not in conventional borders but in great plats thirty feet or so across and deep. Their early summer costume is predominantly cream and white and a dozen shades of purply blue; in one room shading into pale pink, in another into stronger yellows – but in gentle transitions that only dawn on you as you rest your eyes on the whole panorama.

The Festival unfolded in the same seamless way, moving from the fundamentals of garden philosophy to depths of practical experience, represented by Piet Oudolf, the blunt authoritative Dutch designer who has made the whole world plant grasses. (No grasses could be more beautiful, though, than the rippling filigree of the meadows round the garden we were in).

Christopher Woodward, the museum’s hyper-energized director, pursued the vision of Arcadia with Adam Nicholson – himself a practitioner of moving prose. Sue Stuart-Smith spoke with extraordinary insight on the therapeutic properties of gardening, Hugh Cavendish talked about Holker, his Cumbrian estate, Sarah Raven about Vita Sackville-West. Anna Pavord talked to John Sales, Penelope Hobhouse to Tom Stuart-Smith…. the cast was exceptional and there wasn’t time to hear them all.

There was music, there were oysters, when night fell the colours of the garden deepened and glowed and a slow river of pale smoke rose vertically from the barbecue fire. It was an ambitious event that succeeded to perfection. How lucky we were to be there.  The museum that does this deserves massive support.

The raw figures are not encouraging. We have swapped our country garden for a city one which is precisely one five-hundred-and-thirty-sixth of the size.  Twelve acres exchanged for just under one thousand square feet. It means a totally different relationship with your plants, a new regime, which could (strangely) become hectically intense, a change down into a very low gear indeed, needing frantic pedalling.

My night thoughts at Saling Hall wandered round the acres enjoying, or dissatisfied with, trees or groups of trees, concerned with blanket weed in a pond or when to cut some long grass. Spring (specially this year) unfolded week by week over a good three months. You could go off for a week without missing anything vital.

Here, in contrast, I will start awake at midnight with a brain wave: the shoot heading up the wall could be tied in a foot to the left; I could remove a couple of leaves to make room for that flower; the pot of lavender would get more sun on a higher step. It’s a hectic little microcosm, held artificially in some sort of equilibrium by constant

adjustments and daily doling out of water, dowsing one plant and letting another go thirsty to toughen it up.

I know the green fly (there are currently three) by name and take a magnifying glass to a spot of mildew. If anything gets out of hand, in other words, I have only myself to blame.

What does our little domain contain? We are still finding out. It has three levels, descending to the kitchen and the shady little patio outside it. The levels are important – and intriguing; the far quarter of the garden (the part that gets most sun) is raised up five steps, fenced off by a stone balustrade, in some ways looking like the poop deck of (shall we say) a frigate. It stands several feet higher than the surrounding gardens beyond its grey-brick walls. How this happened it’s hard to say, except that it was a long time ago; our massive sycamore grows at this level, and you can’t alter the ground level round a tree.

In any case the poop gives a good view back towards the back of the house, which in turn has a ground-floor balcony, so at each end there is a comprehensive view, as from a hill into a valley. (See, my delusions have started already). A relatively broad path leads up the centre, edged with box. Its stone matches the grey London brick of the walls. It widens in the centre to make room for a table, pots, a Mr Spit face splashing into a tiny basin. Whenever it was built (I suppose in the 1970s) it was done well, with good materials. The walls are trellised to nine feet or so and carry a green load of ivy, climbing hydrangeas, roses, honeysuckle and jasmine. It is a well-furnished box, into which I plan to pack all sorts of joys. We have ordered the greenhouse. There won’t be room to even tickle a cat.