We landed in Normandy on D-day, eighty years after the event, to find jeeps clogging the roads, a sea of ancient khaki uniforms and veteran Dakotas roaring over the surf. But it was another British connection that brought us; we came to revisit the most beautiful English garden in France. How many people know that one of the best of the famous collaborations between Gertrude Jekyll and Edwin Lutyens is on the other side of the Channel? Literally ‘on’. The thirty acres of Le Bois des Moutiers tumbles dramatically down to a cliff-edge and the sea. The garden, and one of Lutyens’ most successful country houses, was commissioned by the Mallet family of bankers at the end of the 19th century. If you book a visit there is still a member of the family to show you round, though today it belongs to the Seydoux, owners of most of France’s cinemas. In 130-odd years it has matured into something that would give its planters justified joy.

Lutyens hit mid-season form with the house; serenely simple at first sight but with precise details that sometimes seem to refer to Gaudi. The partnership with Jekyll gives the surrounding more or less formal gardens complete authority; it is hard to imagine them being otherwise. To the south they melt into orchards, then reach the edge of a slope that comes, in what in Devon would be called a combe, down to the cliff edge far below and what the French, with perhaps unintended poetry, call ‘le grand large’.

The garden, and Vasterival, another woodland treasury of plants created in the 1950s by Princess Greta Sturza, a former Wimbledon champion, face each other across the valley above the sea. The little village of Varengeville, south of Dieppe, is known for its cliff-top church with a richly blue stained glass window by Georges Braque. And inland lies the pastoral Pays d’Auge, source of butter, cider and Calvados.

Sod’s Law visits Chelsea. Monday, Press Day, the royal inspection and the only time you can wander in relative ease round a show without a crowd, was a perfect summer’s day: light sun, a faint breeze under a cloudless sky. Tuesday; cool, sky grey and drizzle turning to rain.

There are fewer Show Gardens than in the past, but one or two were memorable. Trad’s Garden of the Show rarely chimes with the official judgement; it’s the same with wine ratings, but then I’m a heedless hedonist. My favourite was the Roman villa, complete with attendants (not, I think, ‘enslaved persons’) in togas. I don’t know whether the water dripping quietly from the eaves into a marble channel in the floor was really a Roman trick to cool the loggia, but I hope so. (By Tuesday of course it was unneeded; the heavens did the job).

The actual gardens, to my taste, were predictably more about ‘sustainability’ than beauty – or even use. I suspect Tom Stuart-Smith will be rated one day as the Repton of our time: his touch is so sure, authoritative, stylish but somehow realistic and comfortable. His palette this year was calmly green and white, with some purple for contrast. His biggest plants were, of all quiet things, three ordinary hazel bushes of significant size. A substantial wooden hut, a stone water tank and a cluster of clay pots set the tone of almost humdrum existence heightened by intelligent, rather than eye-catching, planting.

There are some colours that burst on us once a year, without precedent: unique, exciting and transient. The new leaves of lime trees have the stage this week; a colour that by coincidence we tend to call lime-green – referring, though, to the citrus fruit rather than one of our champion park trees. Each April I amble round Kensington Gardens, pausing at tree after tree to enjoy the glowing tenderness of the unfolding buds, the little shining package of the leaf pushing out, limp for a day before breathing gives it strength to open to a pale green oval.

Limes were the chosen show-trees of the Georgians. They imported them in thousands from Dutch nurseries to plant their avenues. Kensington Palace has a great crinoline of them centred on the Round Pond, planted perhaps by Queen Charlotte, replanted in the past twenty years or so and now brilliantly verdant, the epitome of a stately spring.

Our little box hedges seem to be almost the last of this threatened species in the neighbourhood. The box moth caterpillar or the blight has either put paid to the rest or their proprietors have despaired of their survival, rooted them out and planted one of the proposed substitutes. Rassells Nursery just across the road follows RHS advice and proposes Ilex crenata, which superficially resembles box. Some nurseries have even cooked up a cunning new name and sell the little holly as Luxus.

It has an upright growth, unlike box, but can be clipped to grow into a flat-topped little hedge that will grow (they say) no faster than box. It may not be as tolerant as box to either drought or too much moisture but is apparently subject to a nasty-sounding black root rot. Nor does it have the slightly foxy smell in the rain that some people hate (and I find part of box’s charm).

For myself, I will go on defending our box hedges, the very definition of our garden, while I can. We use moth-traps and Py spray. We pick off the caterpillars and squish them as soon as we see them. I fear it can’t go on for ever, but while we’re around our box will have all the protection we can give it.

Sixteen degrees on February 16 doesn’t sound or feel right. The magnolia in the front garden looks ready to burst its buds. Primroses are even fading on the north side of the house. Daphnes are in full fragrant flower and the flowering currant is already giving off its Marmite smell. Camellias are in full bloom and in the water tank the fish look distinctly frisky.

Last night we slept with the French windows open. We see summer blouses on the street. The weather forecast shows no hint of winter returning to duty. Should we be alarmed? And is there anything we can do?

The horticultural answer is yes: take advantage. And take precautions. Bring the swelling buds into the house to enjoy them, and try to stop the greenhouse from becoming a hothouse by shading during the day and ventilating day and night.

Now its February 20; the mercury has dropped three degrees and low clouds have hidden the sun. The magnolia has shed all its furry bracts, leaving its purple flowers closed but naked like dark flames among the grey branches. The cercidphyllum that hangs weeping over the pavement is opening its first tiny heart-shaped leaves at the tip of each branch. Crocuses that have found their way into the front garden beds are starting to clump up and a fresh crop of purple flowers are pushing up through the tangle of leaves of Iris unguicularis. It’s a badly designed plant; its leaves succeed in hiding its flowers.

A fat bag of mulch has just arrived form Rassell’s nursery across Earls Court Road. Spreading it is my next job.

Trees may be slow but forests are fast. That’s how it seems to me in our Welsh woods. We were honoured last year with a visit from the Royal Forestry Society (or at least its North Wales Division), and I recalled how things have changed in the 29 years we have been in charge.

What is still recognizable are the contours; slopes of five hundred feet or so from the valley to a ridge, commanding a huge view across the sea towards the Wicklow Hills, and south to the rocky north face of Cader Idris (a mountain more noted for its bulk than its height). That is the airy mountain component. The rushy glen is the course of the Afon Dwynant, from a few springs high on the hill to a burbling, occasionally rushing stream as wide as a country road that eventually tips into the estuary of the Mawdach. The estuary is lined with what is termed ‘Atlantic Oak Woodland’, a precious zone where contorted oaks thrust up from a bed of boulders with only moss and ferns for company. Last year there was no rain for week after week. The hillside springs were dry, with a surprising effect: without moisture they appeared as brown, even scorched, patches in the grass and heather.

The rotation of a commercial forest (as much of ours is) is about sixty years. The tallest remaining trees from the last major plantation , in the 1990s, are spruces almost a hundred feet high and larches, perhaps eighty feet but incomparably beautiful, their delicate canopies soaring on ramrod trunks to form airy colonnades.

Foresters talk about ‘yield-class’, a figure denoting the number of cubic metres of timber produced in a year per hectare – depending, of course, on many factors. Inevitably, sadly, the star performers are always the aggressive Sitka spruce, black in the landscape, spiky to touch. They don’t seem to care if it’s bog or rock; you don’t even have to plant them; their self-sown seedlings sprout everywhere. Foresters say ‘re-gen’, often so dense that it needs ‘re-spacing’.

Our policy is to leaven our money-making blocks of Sitka with admixtures of other conifers, usually larch, or a scattering of broadleaves, which could be beech, birch (which comes up anyway), alder, wild cherry or even Norway maple. Oak is too slow in getting started. Larch, tragically, is suffering and dying from a virulent form of Phytophthora. The lovely Western hemlock, with drooping sprays of bright apple green, is prolific, and can be vigorous enough to hold its own – though sadly sawmills, the market for all our trees, have problems using it and prefer the conventional spruce. Then there is birch and rowan, the sweet-smelling gorse, and of course bracken and brambles. The forest is never dull.

Sixteen degrees on February 16 doesn’t sound or feel right. The magnolia in the front garden looks ready to burst its buds. Primroses are even fading on the north side of the house. Daphnes are in full fragrant flower and the flowering currant is already giving off its Marmite smell. Camellias are in full bloom and in the water tank the fish look distinctly frisky.

Last night we slept with the French windows open. We see summer blouses on the street. The weather forecast shows no hint of winter returning to duty. Should we be alarmed? And is there anything we can do?

The horticultural answer is yes: take advantage. And take precautions. Bring the swelling buds into the house and try to stop the greenhouse from becoming a hot house by shading during the day and ventilating day and night.

Now its February 20; the mercury has dropped three degrees and low clouds have hidden the sun. The magnolia has shed all its furry bracts, leaving its purple flowers closed but naked like dark flames among the grey branches. The cercidiphyllum that hangs weeping over our boundary and the pavement is opening its first tiny heart-shaped leaves at the tip of each branch. Crocuses that have found their way into the front garden beds are starting to clump up, and a fresh crop of purple flowers are pushing up through the tangle of leaves of Iris unguicularis. It’s a badly designed plant; its leaves succeed in hiding its flowers.

A fat bag of mulch has just arrived form Rassell’s nursery across Earls Court Road. Spreading it is my next job.

Mist has gathered in the valley where sheep dot the emerald green with white. High on the hill it blows in scraps and longer straggling clouds across the black of spruce and fir. Between the two sun is reaching a tapestry of trees, finding bright gold in the larches, richer, deeper gold in maples, bone-grey in ashes and a lively yellow-brown in the swathes of bracken. Bracken in the sun is the dominant eye-catcher, and seems to grow more dominant every year.

You get the feeling, sometimes, that bracken will one day smother everything. Yet it’s scarcely a new invention. The diary of the farmer at Sylfaen next door in the 1870s speaks of the bracken-crop in autumn as one of the worst tasks of the year, It was used for animal bedding, but gathering it meant breathing in clouds of its spores, which turned out to be carcinogenic.

Bracken is apparently a universal weed. Antarctica is the only continent without it. It can grow up to ten feet high and spread with its rhizomes hundreds of yards. It won’t grow in boggy ground, so the drainage of uplands only encourages it, but is otherwise unfussy about soils. It laughs off authorized weedkillers. Its roots survive the sharp trotters of sheep. Clodhopping cows are better at breaking them up, but only repeated trampling year after year suppresses them. So expect to see more of it somewhere near you.