I admit I had never noticed the church opposite Waterloo Station before – nor its garden. St John the Evangelist is, appropriately enough, one of the four ‘Waterloo’ churches built with a million pound grant from parliament after the battle we are celebrating in June. It apparently looked out of date in the 1820s when Gothic was the new approved ecclesiastical style; people thought its splendid Grecian portico, however dignified, was old hat.

Its generous burial ground is now a model urban public garden, admirably planted, well maintained and with lots of green space for games and picnics. The very opposite, in fact, to the proposed Garden Bridge which was the reason for my visit. I was asked to speak at a public meeting against the project from the gardener’s point of view. The church was packed with objectors, invited by the newly-coined TCOS (or Thames Central Open Spaces). Most of the objections centred on the cost of building and running this odd hybrid, and whether ‘public’ money should be spent on it. The cycling lobby is furious that you can’t bike over it; the disabled that it won’t (or rather wouldn’t) be wheelchair-friendly, and everybody that it would effectively be another commercial space for holding events, closable at will, and not a proper public bridge at all.

I made the point that it is a crazy place to put a garden. Artist’s mock-ups show it as a sort of park with full-sized trees. What tree would grow properly in what is essentially a long thin planter exposed to every wind that blows? The essence of a garden is shelter, seclusion, and space to linger. The plans show the bridge would have none of these. At busy times it could be like the Chelsea Flower Show; necks craning to see any plants at all.

But the greatest objection of all, overriding all other considerations, is the casual way that Boris, his friend Joanna and their star designer, Thos Heatherwick, would override the history that has created London’s greatest spectacle; the grey tideway of the Thames hurrying, dawdling, rising and falling between its gritty beaches, its monumental banks and its serious, grownup bridges. They would stick their folly in the finest view of all with, as The Times wrote, ‘all the elegance of a Saudi prince’s gilded loo’ – and just as much relevance.

There is a judicial review of Boris’s unorthodox procedures scheduled for June. Money is needed to pay for it. Please visit the TCOS website and make a contribution.

Perhaps I shouldn’t have fed the brutes. May always catches me out. For weeks we enjoy the slow unfurling of spring; then suddenly, one day in May when we’ve made other plans, every plant in the garden shouts for attention. Its flower-buds start to open or its shoots zoom out and block your path. Or shoots that looked full of promise suddenly flop.

If there’s never enough time to keep up with what’s happening, let alone drink in the beauty of it all, the pressure of planting and pruning and staking and generally maintaining order keeps me outside until I need a torch to see what I’m doing. Then I have the drink I sorely need and forget what it was.

So, today, I have planted six things, fed all the pots, taken cuttings of salvias and fuchsias and pelargoniums, fed the agapanthus, restrained the solanum, shown roses and clematis which way to go, clipped box hedges, spread manure, given the vine weevil something nasty, and changed my mind ten times.

I’m not, I fear, the most realistic gardener. I plant things that I know will grow too big (that solanum, for one). I dream that miserably unsuitable and sickly plants will recover, that dust is fertile and shade sunny, and that, as Christopher Lloyd once crushingly said, all my geese are swans. And it hasn’t taught me a thing.

At the same time I’m timid. I imagine new schemes but don’t do anything about them. I stick to plants I know; a better variety is out there, I expect, but I love the original. ‘New’ is my least favourite word: the catalogue goes straight in the bin. I’m upset by change for change’s sake. When they altered ‘them’ (that trespass against us) to ‘those’ I wrote to the archbishop.

Cows in the distance keep the bass line going; sheep are the counter-tenors; a trickle from a stone lion’s mouth is a flute obligato and a hooting owl makes random entrances. I am sitting in an Edwardian garden, defined by stone balustrades, on a Welsh hillside. A huge horse chestnut is lit by the moon and its hundred thousand candles. A white-flowered cherry poses stiff and symmetrical against a gothic frieze of firs. I walk back to the house and its aura of woodsmoke, to be stopped by a scent of honey that completely takes over. From what flowers? There is a pale shape just beyond the balustrade: Pittosporum tenuifolium. I had no idea its tiny black-purple flowers could fill the night like honeysuckle.

We stay in this wonderful survivor of a garden each time we come to Wales to walk in our woods. In early May, with luck, we watch our blue rhododendrons and the little Welsh bluebells in bloom together under the grass-green canopy of beech and larch. Welsh bluebells, at least in Snowdonia, are tiny, and almost royal blue. Rhododendron augustinii ranges from blue-grey to purple, a small-leaved open plant which is inherently graceful – and with royal blue and grass-green, when the clouds part, a sight I happily cross the country to see.

And the garden? It belongs to a comfortable country house hotel with kind hosts, friendly staff, delicious food, and wine at modest prices. Only its name causes stress: Penmaenuchaf Hall.

Most gardeners, I suspect, worry about weather, tenderness, colours, slugs, aphids, how quickly and how big things will grow…. in their own order of priorities. My concern is just how many plants I can fit in to my diminutive patch. And I mean different plants.

This is no way to garden. It’s bound to be a dog’s breakfast. ‘Cottage’ is the politest thing you can say about a random muddle of favourites. ‘Short at the front, tall at the back’ hardy applies when the front and back are three feet apart. The one factor I do discriminate about is colour. White is good (it shows up in the shade). Blue is better. And yellow, at the right moment and beside the right blue, can be just the thing. Colour hits your eye in a different dimension from size or texture. Just now some Viola labradorica (not really blue, I know) is flowering in crevices where the seed has lodged. It is right beside a primrose. That little duo is a jewel.They come and go, these little treats. Persistence is not their strength (though primroses go on and on). But so do I come and go; what matters is that I notice them again and again, and each time get a thrill. Is this ‘mindfulness’? It’s a quite different pleasure, and attitude, from the repeated leisurely – and of course critical – survey of carefully planned borders.

The ceanothus is in flower, and so are the pale yellow wallflowers I cut back last year. A pulmonaria is almost gentian blue. And the amazing tulip Ballerina is flaming orange, with just enough yellow at the tips of its pointed petals to count. It stands two foot six high (I’ve just measured it), its flowers held vertical on the end of its long swooping stems. Why amazing? Because unique among tulips – as far as I know – it has a scent, somewhere between freesias and apricots. Andrew Marvell wrote ‘Make that the tulip may have share of sweetness, Seeing she is fair’. God (or a Dutchman) listened

Over Robinson's wall

Why have I neglected Gravetye Manor for so long? We used to be regular visitors to William Robinson’s old garden, enjoying its renaissance as a hotel with an owner, Peter Herbert, who very much got the point and restored the essentials of the garden round the splendid Elizabethan house. His thirty-odd year reign there settled Gravetye as the base of choice for exploring the most densely-gardened corner of England, with a dozen notable gardens within easy reach. And his care for the table was equally rewarding.

A new owner with deep pockets, Jeremy Hosking, has since given the hotel and the garden another uplift; renaissance is the word being used again. Five years ago he tempted Tom Coward from Great Dixter, where he was working with Fergus Garrett, to take over and complete the restoration . What would Wiliam Robinson have done with modern plant s and methods (if with rather less than his army of gardeners)? Wandering in this extraordinary place one can glean some idea.

This is a heady spring to visit any garden in the south of England. Nothing has interrupted the budding and blossoming since the new

year. Each morning at home we draw the curtains to see long branches of blossom on the double white cherry in the street, our pink magnolia in the front garden, and the sumptuous sight of our neighbour’s weeping cercidiphyllum, a cascade of circular leaves of fresh lawn-grass green hiding the street. I laze in bed for five minutes counting the planes pass through the blossom as they line up for Heathrow.Gravetye in mid-April was inebriating. In the parterre west of the house the sharp sunlight focussed each flower and lit the tulips like gemstones, a cacophony of laughing colours . The peculiarity of Gravetye is that the whole garden seems to face south. It lies, drinking in the sun, above a wildflower meadow sloping south-west down to a lake. Always on the lookout for plants flourishing in shade I drew a blank.

The Robinson style is all about detail; plants ingeniously mixed to harmonize, flowers chosen to complement one another and give the impression that The Creator had had a particularly good day, unaided by man. They didn’t use the term plantsmanship in those days, but this (rather than collecting rarities) is the true meaning of the word.

The magnum opus of the moment is bringing the walled kitchen garden back to life and productivity. It lies up the hill a hundred yards from the rest on the edge of the forest of 1,000 acres that Robinson planted or assembled. Perhaps there are other circular ones; I don’t know. Many certainly have curving walls to the north to trap the heat. But this is like an elaborate enamel brooch, the centre striped with different vegetables and the circumference ringed with soft fruit and wall-trained trees,

Tom Coward has written in Country Life about the logistics of gardener and chef working in tandem. Whether it always goes perfectly to plan or not, it is part of the romantic horticultural dream that Gravetye represents.

My occasional correspondent in Japan can react with charming enthusiasm to things I write. She frequently provides me with facts I would never find without her. She also, quite unwittingly, gives me the feeling that we in the west are all novices at the game. The Japanese have been enlightened, demanding, hugely ambitious and intensely focused gardeners for twice or three times as long as we Europeans. They were developing techniques and collecting and breeding plants and refining their taste, while we still thought a Hortus Conclusus was a pretty nifty bit of avant-garde thinking.

Take the flowering cherry. We date our appreciation of these springtime wonders back just over a century. They even have the reputation here (with some justification) of being short-lived; just instant décor.

The whole deal is different in Japan. The population puts on its Sunday suit to greet them, picnics on the grass (lots of sake) and gives them National Monument status. My pen-friend sent me this postcard of a weeping cherry that Engelbert Kaempfer might have seen on his visit to Odawara in 1691.

This was in reaction to my story about the Californian James Light, his glasshouse and his orchards where Silicon Valley now stands. Her great grandfather had a plum orchard on the very spot. Japanese gardeners are still relatively common in California today. He installed his family on San Francisco Bay early in the last century. He had to retreat back to his family in Japan in the 1930s when Wall Street crashed. Then came the war and he never returned.

Scrubbed clean

I was quite keen on the mossy look at first. In a largely paved garden a hint of green on and between the paving stones softened their harshness. It seemed to show that nature was accepting the intrusion. Someone, it seemed, had slipped a green filter over my specs. I rather liked the effect.

But then the green started spreading. It tinted the floor, the brick walls, the base of the greenhouse, and in due course the teak table and chairs. Seeds germinated between the slabs. I like violas and hellebores and foxgloves and campanulas – especially C. persicifolia – but I don’t want to tread on them. Without a modicum of spit and polish a town garden can start to look scruffy. So we accepted the offer of a clean-up with a high pressure hose. The green sluiced away was replaced with shades of ‘natural’. Now we hope the scrubbed-clean look won’t last too long.

What did I think of artificial grass, someone asked me the other evening – tentatively, almost shamefacedly, I sensed – as though suggesting something indecent, or expecting a put-down. Why on earth not? A little patch of lawn in London is usually a sad thing. A mower is clumsy in a small space. And as soon as the football comes out you have a patch of mud.

We are almost wholly paved, so it doesn’t arise, but our daughter over in Fulham is investigating a carpet lawn for her children to roll around on. The website she sent me to comes up with a surprising range; the poshest called Mayfair (New for 2015!), then presumably in descending order of poshness, Kensington, Chelsea Super Soft, Wentworth, Holland Park, Belgravia and Knightsbridge. The ‘turf’ is laid on a porous ‘shockpad’ to make it springy underfoot. All you do, apparently, is brush it now and then. Should we, come to think of it, start thinking green in a more positive sense?

Would you hurry to buy a book from the East Bay Municipal Utilities District? That’s what I thought. I don’t know about EBMUD’s other publications, but their Plants and Landscapes for Summer-Dry Climates is the best on this timely topic I’ve yet seen. It weighs about 4 lbs, but its design, organization, illustrations, photography, printing and above all its style of writing are as clear, useful and attractive as they could be. The author/editor is Nora Harlow, the excellent phtographer Saxon Holt.

Its subject is the San Francisco Bay area. Obviously many of the plants it lists would be tender in most of Britain. But its principles and the imaginative solutions it describes could be applied anywhere. People with Mediterranean gardens should grab a copy. Definitely my book of the year so far.