The rain gave the procession an authenticity that a day of glittering helmets might have lacked. Or perhaps reminded us of glittering sunshine at a Windsor wedding not long ago that came to grief. The weather had given the Royal gardeners anxious weeks recently. A Spring so uncertain and late makes ceremonial bedding even trickier than usual. The scarlet tulips at Buckingham Palace, calculated to bloom for the Coronation, were so late in opening that I gather the gardeners had pelargoniums ready to take their place at the last minute. Happily, slightly warmer days encouraged the tulips; they shot up to be on parade with the guards on the day.

Coronation Day and the first aphid squish of the year. Roses in bud and greenfly at work. The first roses here are the notionally perpetual Parson’s Pink China and Mad Alf (aka Madame Alfred Carrière) already twenty feet up the sycamore. I can’t reach the buds on Mad Alf to tackle the greenfly but the little china rose droops over a camellia close at hand. It’s pale pink, soft and drooping at the first raindrops; an unpretentious thing, but with a famous history as one of the original progenitors of the roses that keep flowering, when conditions are right, almost year round: hence its alternative name of the Monthly Rose. I don’t really recommend it. It is the present performance of a plant that matters – except to historically-minded romantics like me. Who of course have a field day at coronations.

If you want to be sure to keep any plant you should give it away. It’s the gardener’s reinsurance policy. Give it, of course, to someone with green fingers who can give it, cutting or seed, back if you then lose it.

I reinsured a lovely white-flowering form of Honesty, doling out its seed to anyone who admired it. When it flowered in conjunction with its transparent seed-capsules it lit up its corner. Where is it now?

It’s been a near-perfect planting season – at least for spring planters like me. The heavens have been generous with timely rain; our streams are racing as I have rarely seen them. In the New Forest the ponies are splashing through gleaming puddles that are almost ponds. The first thrilling flush of foliage is filling out while the flowing trees, cherries and crab-apples and especially magnolias, grab all the attention in the landscape.

Aren’t our public bodies too austere in their tree-planting taste? Our planted woods could do with more variety. We don’t lack autumn colours. Oaks alone produce a medley. But I always plant a scattering of Prunus avium, our native cherry, even among conifers. Recently in Wales I have planted a scattering of Norway maples, cheerful with their lime-green flowers in April and reliable bright yellow leaves in late autumn.

Forestry is a deeply conservative art-form. It relies on centuries of experience; anything original is considered dangerously risky when the final reckoning is fifty or a hundred years in the future. You will live with your mistakes for the rest of your life. Gardening of course works in a much shorter timeframe. The safest planting of all is annuals.

It’s a mystery who planted this Kensington street as an arboretum, rather than the conventional avenue. In its four hundred-odd yards we have about fifty different trees, including one I still haven’t been able to name with much assurance. Outside the house we have one of the Council’s favourites, the double-flowered version of our native cherry, Prunus avium Plena; in fact three of them in a row. They must be fifty years old, and as many feet high. Their long branches are supple enough to wave in even faint breezes outside the bedroom window. Flower-buds, now conspicuously knobbly, will soon open to cover the street with a dazzling white cloud.

Across the road a young Prunus sargentii. Sargent’s double pink cherry, brought by the famous director of Boston’s Arnold Arboretum from Japan in 1890, could reach a similar size. Pyrus ‘Chanticleer’ crops up here, as it does almost everywhere in London; a safe but scarcely exciting tree, round here invariably grafted, so it soon sprouts a bush of suckers round its base. Will they never learn? There are several liquidambars, two fastigiate hornbeams, now at their best with catkins and young leaves, a Manna ash across the road and a hawthorn looking very modest among the tall specimens. A solitary plane, on the other hand, looks over-mighty.

Does any conifer make a good street tree? The most prominent planting I can recall is the avenue of Metasequoias along the Cromwell Road extension in Chiswick. If the function of a street tree is to provide shade, they fail. They form a green (in summer) curtain, but a fairly dismal row of sticks in winter. Is there an ideal? They must be in scale with the street; happily this street is double-width – a mini-boulevard, you might say. In wide-enough streets, as an alternative to the magnificent London plane, there is a lot to be said for elms (and very little against them) once we regain confidence in their survival.

Three days in the New Forest on the cusp of spring brought moments of ecstasy; Wordsworth moments. ‘Ten thousand saw I at a glance’. True, there are blowsy daffodils, and self-conscious little ones with long noses; the true excitement for me comes where our modest little native shakes its pale head in spreading crowds. Ten thousand? I couldn’t count, but they spilled over paths, into the gullies brimming from days of rain, clustering under oaks and mobbing the young beeches.

Our little oak wood (perhaps one hundred trees) is threaded with streams that rarely run, but raced to fill three ponds on the way down the hill. The floor is still bare under the hazel coppice; there are bare bushes, and others dripping with bright buff catkins. Among them we have planted a hundred seedlings of Acer palmatum, now four-foot saplings, to see what colours or eccentric shapes of leaf they will produce as they grow up.

We have lined the streams with Rhododendron luteum, the plain yellow azalea, to flower with the bluebells that carpet the wood at the beginning of May and whose leaves are already starting to green the ground. Here and there, as examples to the rank and file, we have planted the two cheer-leaders among acers: Seiryu, delicate-leaved, yellow, green and occasionally orange, and Osakazuki, reliably November scarlet.

The Tokyo cherry, Prunus yedoensis, is ten feet high and already in swelling bud. I have high hopes for the weeping version of Prunus subhirtella, which we have seen stooping low over a pond in a garden near Rome, and which we hope to see admiring its rosy reflexions among the shoals of bright green duckweed. The tall weeping willow on a tiny island is sparse-leaved in the shade of the oaks, dangling its long streamers like the flimsiest of curtains. Young rhododendrons, generous gifts from Exbury ten miles up the road, are yet to show their colours; for the moment it is yellow and blue that dominates among the grey pillars of veteran oaks.

It’s the nice irony of spring that its bright colours and sweet scents arrive simultaneously with biting cold air. Not cold enough, happily, to discourage the heroic little autumn cherry. It takes hard frost, harder than any we have seen in London for many seasons, to spoil the tiny flowers that keep coming from well before Christmas, even late November, until March, or even April.

It’s far from being an original choice, but limited to one tree in a little town garden, is there any better? Its modest presence, light structure, good health, but above all the charm of its months-long flowering has no real rival. If there is a secret to managing it, it is to keep it fairly small. Discourage any hearty growth. Mine is restricted by a 14-inch plastic pot buried in the ground. I’m not sure what goes on down there; I imagine a tight-curled ball of roots. Once it tried a break-out; a root leap-frogged the rim of the pot and began a vigorous freelance career before I noticed it (and a corresponding vigour in the canopy) and chopped it off. Bonsai treatment, in fact, but with no ill results. It forms a delicate pink centrepiece in the green winter garden; I can scarcely ask for more.

Its name, though: Prunus subhirtella ‘Autumnalis’. Whichever botanist coined the name shared the tin ear of many colleagues – but also their short sight. ‘Hirtella’ means ‘hairy’. ‘Sub signifies ‘slightly’. So we are celebrating the slight hairiness of the twigs of a tree that is regaling winter with its mass of delicate flowers. The Japanese have a more expressive name for it. They call it ‘Higan’, the spring equinox, more or less when it is in full bloom – which also means ‘the far shore’, where our ancestors are to be found. So in future it’s Prunus ‘Higan’ for me.

The front of this house is screened from the street by something remarkably like wooden rain, falling into and around the purple flowers just emerging on our magnolia. The rain is the cascading branches of the extraordinary weeping Cercidiphyllum japonicum, growing just on our neighbour’s side of a central camellia hedge. The two, the cercidiphyllum and the magnolia, flower in unison and in contrast: the former (Katsura in Japan, where it is the largest native tree) with tiny pale fringe-like flowers preceding its delicate heart-shaped leaves.

Soaring above them both, as high as the house, is the Council’s double flowered gean, England’s wild cherry in its showiest form. No signs of spring here; just the naked scaffold of disordered grey branches, four of them trunk-like but without a trunk’s conviction, knobbly flower-buds apparently not yet feeling any urge to open. There is a Caucasian maple in the nextdoor front garden, too, another tree left unsupervised to grow errant competing branches and end up a winter eye-sore. The katsura thankfully makes up for it.

Nobody can explain why this street is a sort of linear arboretum with scarcely two trees the same, and three or four decidedly rare. Who do I thank for four seasons of enduring intrigue?

Its biennial tree-pruning time. It’s not the tree that’s biennial, but the massive operation of cutting it down to size. The sycamore at the end of the back garden was a wartime baby. Its girth of 80 inches means it was a sapling in the 1940s, a typical weed sycamore on, I guess, a compost or rubbish heap. There is an unsolved puzzle about our sixty-foot garden: The far twelve feet are four feet higher than the rest, paved, balustraded and reached by four stone steps. They are four feet higher than the surrounding gardens beyond the walls too.

How, and why? The sycamore is on the higher level. Did its seed germinate on a rubbish heap (not unlikely, during the war)? But does it seem probable that someone would pave and balustrade a rubbish heap? Were they simply respecting the roots of a young tree? Many London gardens end with a buried air-raid shelter; there is not one here. For whatever reason our garden is on three levels, the kitchen on the lowest, with the greenhouse on the middle one. It certainly gives it character.

The sycamore, however, is an expensive feature; at more than a thousand pounds every other year you could say a luxury, and one we can’t avoid. Today’s entertainment (and summer shade) is our reward: two athletes up in the canopy, cutting and dropping every whiskery shoot, and two helpers on the ground gathering them and carrying them through the house. There is no side entrance so they come through the narrow hallway, stripped of everything we can move.