While I’ve been mugging up on fruit history I’ve come across a curious strawberry fact. Our big juicy ones superseded the little European native wood (French fraises des bois) or alpine strawberries (some debate here: are they the same or different?) when the American Fragaria virginiana met and married the Chilean F. chiloensis, introduced (the curious fact) by a chap called Frézier (fraisier: geddit?) – or in Scots, come to that, Fraser. Our strawberry’s botanical name is F.x ananassa, ananas being French for pineapple. One of our best and tastiest varieties is ‘Cambridge Late Pine’.

Note to supermarkets: please label our strawberries (and indeed all our fruit) with the name of the variety as well as where it’s grown. And don’t harvest strawberries by cutting off their stalks and leaving just the green ring of bracts. You need the stalk to pull out the central plug when you put the strawberry, crunchy with sugar, in your mouth.

Who said, incidentally, ‘the raspberry is the thinking man’s strawberry’? Discuss.

Louis XVIII is a monarch you don’t hear much about, France’s last and perhaps fattest. He lived for a while at Hartwell House, was too overweight to walk, and had a predegustator who doubled as librarian of his 11,000 books. This chap’s job was, among other things, to pass fruit as acceptable for his majesty.

My authority, Edward Bunyard (d. 1939, pomologist and epicure) relates how everything stopped when Christophe, the gardener, knocked at the library door with a new variety of peach. Petit-Radel, the predegustator, waited while Christophe, with his ivory knife, cut the fruit in four. The first quarter he judged for its juice; the second for its flesh, the third for its aroma and the last for its harmony.

Bunyard, in his Anatomy of Dessert, came down in favour of the nectarine over the peach, on grounds of both its flavour and its smooth skin, though with some reservations about texture: less buttery, more fibrous than the peach. He cites fourteen varieties, and twenty of peaches (La Quintinie, Louis XIV’s gardener at Versailles, listed thirty-three). Since then breeders have selected and bred scores more. Rivers of Sawbridgeworth, for example, offered a whole aviary of peaches with bird-names: Kestrel, Goshawk, Sea Eagle, Peregrine… Apples and pears have been bred in hundreds. Where are they all?

The RHS has given an AGM to a mere five (the nectarines are ‘Lord Napier’ and ‘Early Rivers’, the peaches ‘Duke of York’, ‘Peregrine’ and ‘Rochester’). Look for the name of the variety in a supermarket: the country of origin is usually all we’re told. The truth is we don’t have librarians who predegust or gardeners knocking at their doors. The supermarket buyer predegusts, or certainly should, but is more concerned with price and shelf-life. If a pear needs an alarm clock to announce its fifteen minutes of perfection you won’t find it at Waitrose.

What you do find these days is flat peaches – a happy sport of the ancient fruit that suits both shops and customer (and even waiters: they don’t roll off the plate). Flat peaches grow on the branch face to face, like headphones – another of Chinese nature’s endless repertory of brainwaves. Their flesh is as sweet and juicy as any peach (so juicy there is apparently one variety you can drink with a straw; Louis XVIII would be in raptures). They pack perfectly, tighter than round fruit, to please the carrier. There is even, so I read, a nectarine or fuzz-free kind, though not yet at Waitrose in Kensington. Its name is Mésembrine. My father used to call peach-fuzz ‘goobra feathers’. He wasn’t in favour: definitely a nectarine man. What advance can we hope for next, since we’re doing so well?

The hardest peach to find in a shop is the pêche des vignes, the profusely juicy red-fleshed kind that ripens as late as the grapes in the vineyards where you usually find it planted. It gives the vigneron, they say, an early warning of mildew in the air. You need a bath after eating them, but if by some miracle a flat and fuzz-free sport appeared I’d certainly have a word with Waitrose.

A warm weekend’s visit to the battlefields of the Ypres salient, one hundred years to the day after my father was wounded there by a round from a German Maxim machine-gun. He carried the bullet in his wallet for the rest of his life in an envelope marked “German bullet that wounded G.F.J. in June 1915 at Ypres, taken out at Guy’s Hospital by Sir W. Arbuthnot Lane”

He was secretly rather proud that he was operated on by this famous surgeon (the model, it was said, for Sir Cutler Walpole in the Doctor’s Dilemma), incredibly soon after being wounded. Trains were shuttling the wounded from the front to Calais and London. ‘I woke up’, he wrote to his mother, ‘in a London Hospital’. He was lucky. But six months later he was back with his battery (he was in the artillery) in the same spot.

The cemeteries tell the story of some of the worst battles. The bodies were buried near where they died, at the beginning of the war in nearby churchyards, soon in plots appropriated as cemeteries. One of the biggest, with 12,000 graves, is beside the principal ‘dressing station’ by the railway.

The cemeteries are gardened by The Commonwealth War Graves Commission, to a standard the Royal Parks would be proud of. There are many miles of straight edges and immaculate hedges with white headstones in parade order. Some have pavilions or cloisters whose walls carry the endless lists of the dead, listed by regiment. Tens of thousands are anonymous, but those that were identified carry the name, rank and regiment of the soldier, and most of them his age, very often between 19 and 25. In June scarlet roses and bright purple lavender form our tricolour with the white Hopton Wood stone that was generally used. Their trees form an arboretum, interestingly chosen and perfectly kept. There is much to learn in these battlefields – even about gardening.

My brother-in-law, Simon Relph, has made a beautiful and ingenious little garden behind the 14th century farmhouse by the famous tithe barn at Bradford on Avon. Its glowing stone gable peeps through the walnut tree at the end. Simon has contrived lawn, pond, terrace and a rich choice of plants and left himself room for an immaculate vegetable garden, framed last weekend by roses at their peak. “Rambling Rector” spreads its froth of flowers for fifteen yards along the old stone wall.

But they’re moving house. A lucky successor will inherit five years’ work. We were taken to see his next intended project, a modern house with three times the garden space – and I confess to a twinge of envy. If he can encapsulate so much in the confines of the old farmhouse yard what fun he’ll have with this almost-virgin territory.

We discussed the trees. They are the first and most crucial decision in any new garden. How do you weigh the fact of an established but dull tree against the chance of choosing something better? Of course you plan for both. A few are so revolting that the chop can’t come soon enough. A worn-out Prunus amanogawa (the pink cherry that apes a Lombardy poplar) is instant firewood. A droopy old Lawson cypress might be spared (but mainly on the grounds that it isn’t a Leyland). A dingy purple plum gets its quietus (not to mention that most villainous of shrubs, the yellow-leaved choisia). What to do with a misshapen neglected ash? A clever surgeon could improve it. But there’s a centenarian beech to one side and a thriving walnut in the middle. And space for fruit trees, magnolias, dogwoods,…

My instinct (not that it’s my garden) is to consider the light and shade first. Decide where you’ll want lunch on a hot sunny day. Make your shady spots as appealing as you can. White furniture under a handsome tree draws people’s feet like a magnet.

Next comes the division of space; the apportioning of rooms. Will it be explicit, as in clipped hedges, as implied by the massing of plants? Or, of course, both? I can’t wait to see it take shape.

The Piet Oudolf garden at Bruton belongs firmly in the present, Oudolf was given a sloping field beside the new Hauser & Wirth art gallery (whose restaurant, a sort of tidied-up Petersham Nurseries in Skye Gingell’s day, vaut le détour). Oudolf, as everyone knows, plants abstracts with sinuous blocks of “prairie” plants. There are no impediments to your eyes wandering over a vast field – nor any plan, it seems to me, in the paths wandering round the beds. You can romanticize about the sense of space, the breadth of the sky, the movement of the wind in the (many) grasses. The two garden essentials of shelter and seclusion are totally absent. Do they (as I half suspect) represent, to a right-on modern world, infected with socialism, the privileges of privacy – or indeed the privacy of privilege?

Here’s a simple rule for creating a memorable garden: choose a south-sloping hill with a gushing spring at the top. Then tease the water down, across, fast and slow: play with it; let it lie in pools and splash down steps, shallow steps and steep ones, singing different tunes.

This is the formula at Shute House in Dorset, refined to concert-pitch by Sir Geoffrey Jellicoe over many years for Ann and Michael Tree. It put me in mind of Ninfa, that supremely hydraulic garden south of Rome, where a crystal river races through the ruins of a medieval city. Shute is the English Pastoral version, smaller, quieter, shady rather than sun-baked, but equally haunted by Naiads, the nymphs of springs and streams and pools.

Did I hear that Romans discovered the spring at Shute Hill? If they were ever here they could hardly have missed it, and knowing their taste for water they would surely have made the most of it. It rises, these days, in a circular pond perhaps twenty feet across, half-lost (and half-found) in thick curtains of laurel and rhododendrons.

So much water wells up from the crystal depths that it leaps down the overflow to ripple the surfaces of a pièce d’eau perhaps a hundred yards long, a dog-leg shape so designed as to seem two different ponds. One is sinuous, a little Stourhead banked with lawns and rhododendrons and navigated by black swans, the other a calm canal contained in high beech hedges, leading to a deft sketch of a Roman theatre.

The divided waters continue on their separate ways. From Stourhead they tumble into another informal pond and continue as a shady stream crisscrossed with meandering woodland paths. From the canal they emerge under tight control in a garden of stepped terraces, splashing and gurgling between parterres full of every plant that loves moisture and warmth.

That game over another begins: a racing runnel down a grassy glade; leaping with such brio into three hexagonal ponds that the pressure feeds little fountains to ruffle their mirrors. Each leap is a little organ of pipes tuned in a different key; the air is full of watery notes, from murmur to tinkle, through bubble and splash.

That long-disused word ‘felicities’ needs reviving to describe the various incidents en route. There are arches leading to more enclosures, more parterres of bold planting, little bridges and towering trees. The classical stone house lies to one side, its terrace surveying a long view to distant downs and the next destination of the playful water: more ponds in the fields to reflect a cloud-banked sky.

To Kew on a perfect June day for a serious all-day session on, of all things, tree safety. The IDS organised the seminar with Tony Kirkham, the head of the arboretum, as a consequence of his horrific week in court last year when a branch fell off a cedar and killed a girl.

Accidents and Acts of God are old-fashioned concepts with little, if any, place in current law; the blame culture has to pin every misadventure on a cause, and the cause on an individual. The Royal Botanical Gardens owned the tree (a cedar of Lebanon); Tony Kirkham is responsible for all the 14,000 trees in the collection. If a tree is unsafe (the presumption if it sheds a branch) it should have been made safe. Under Health & Safety laws Tony might have had to go to jail.

His audience yesterday were people who either own or manage trees in arboreta or parks all over the country. I think they were shocked, all of them, at the risks they are running in letting anyone near their trees. Their duty of care extends to every tree and every branch, and the only way to satisfy a court is to show that you have inspected the tree in question, satisfied yourself that it is not about to break up, and kept records of your inspection. It is only the fact that Kew does have a long-term, fairly elaborate and fully documented inspection regime that saved Tony from clink.

True the family of the unfortunate girl were on the attack, hired a QC and an expert (who turned out to be not extremely so in court). We were full of questions. Does the duty to inspect apply to trees in ordinary gardens? (Yes). Does it apply to trees in woodlands or forests? (Yes). What about the notorious and mysterious phenomenon of ‘Summer Branch Drop’, when a major branch parts company with its tree without warning, for no perceptible cause? For some (or no) reason this happens most often in June, July or August. There is even a superstition that the time to stay away from trees is on July 22 and 23. Tree professionals prefer to let S.B.D stand for Sudden, rather than Summer, Branch Drop – not having a clue how it relates to a particular season.

We spent the afternoon on a practical tree-inspection tour of the arboretum, following Kew’s three-stage system: first walk (or even drive) by at 3 mph with your eyes skinned, looking for broken or split branches, splits in trunks, signs of weeping or surface fungi. This you should do as often as possible, within reason. The second stage is to come back and examine what you spotted. Carry a mallet to tap the trunk for hollow resonance and an iron rod to prod the base for soft wood. Take action as needed: cut unsafe branches straight away.

Stage three is for when you can’t tell, or decide, because the problem is hidden inside. This is when the expensive toys come out: an electronic device called a Picus Sonic Tomograph that reads the speed of sound-waves through the trunk to build up a picture of the interior. You hit a nail at intervals round the tree; the sound travels fast through sound wood, slowly through rotten wood and not at all through hollow cavities. The rule of thumb is that if one-third of the trunk is solid the tree can stand. Less than that means the chop.

Of course other factors come into it. A hazard (the possibility of something going wrong) is not the same as a risk (the chances of it doing damage). There is obviously more risk where more people congregate, by a path or a road, then in the middle of a wood. Your action can be proportional to the risk, so when a grand old specimen by a path begins to look a bit wonky Tony Kirkham’s first step is to move the path. More people walk on short grass than long, so he lets the grass grow or creates a wide circle of mulch around the trunk (which is also, of course, good for the tree). There is obviously a degree of proportionality in the precautions you must take – but the fact remains, the buck stops with you.

And you must contemplate the possibility of extreme bad luck: the Kew cedar branch not only brought down two others, but a huge chunk of wood bounced. The poor girl was six metres outside the radius of the tree.

It was a landmark case. Not long afterwards the National Trust was able to use the same defence of regular inspection and records. But it sent a shudder through the gathering. We all went home to brush up our logbooks.

Another six-day excursion, this time to the Gers, Armagnac country north-west of Toulouse. Four days with afternoon temperatures of 35c or 95F produced miraculous changes in the richly farmed landscape. Seedling crops appeared in immaculate emerald rows from the bare earth. Crops that were in that embryo stage one day shot to bushy bulk three days later. Grasses started to flower, tinting the fields, and the patchwork of the woods in half a dozen greens moved perceptibly towards the sombre uniformity of summer.

It is a landscape where each prominent hill has its bastide, ranging from a single tower to a small hill-town, ringed with woods. From its walls you look down into bowls of fertility. Wheat, sunflowers, corn, potatoes, tobacco, rape and even peanuts fill the valley slopes with varied colours. From our hosts’ house delicious glimpses between copses of oak or elm or pale walls of ancient stone change with the circling sun or the unpredictable moon. Their soundtrack changes, too: from the clamour of swallows to the hoot of hoopoes to the mesmeric solos of a nightingale.

Meanwhile in London a couple of warm days had brought the garden, when we got home, into its first phase of summer colour; quiet in our shady beds, campanulas and white foxgloves and the new tawny fronds of ferns, cheerful on the walls with pale clematis, roses Bantry Bay, Gloire de Dijon, Iceberg, Phyllis Bide and Alister Stella Gray, and raucous above, where our neighbours’ roses, unrestrained, wave fat blooms in red, white and pink above the foam of climbing hydrangeas.

Ambiguous robinia in Tokaj

A weekend in Hungary to see the Tokaji vineyards in their spring finery: hillside after hillside covered in files of the singular pale green of young vine-shoots. The shoots are three feet long, up to the top wire of the trellises, their flowerbuds visible, utterly vulnerable to a frost – unlikely in late May but still conceivable. And a horrible black hail-cloud sailed by this afternoon.

The village gardens and the forests on the hilltops are at their best: forests in their primitive state, a mixture of every imaginable species, unplanted, unthinned, seemingly impenetrable until you come to a stream winding down a shady valley, gardens brimming with pale flowers; irises and peonies the favourites. Roadsides are full of wild roses, pink campion, purple sage and blue vetch.

The forests have a problem, though: the invasion of robinia (or as we tend to call it) acacia. At our old home in the centre of France, in the Foret de Trançais, where the oak is supremely “prestigieux”, robinia crops up everywhere except deep in shady woods – and sometimes has a go even there. Every roadside is lined with it, suckering and seeding prodigiously. Its thorny progeny are good at self-defence. In May and June its masses of white blossom are popular with passers-by. Then its dreary little leaves dominate the rich mixture of textures and hues of the native trees.

How did it spread so far and so successfully? Presumably France had its equivalent to William Cobbett, who so enthused about the peerless value of this new import from America – named, by the way, after Jean Robin, director of the Paris Jardin des Plantes. Its timber makes the best fence- or vine-stakes, splitting easily and impervious to rot. There is even a fashion for using it for barrels, too, especially for sweet white wines. So farmers must have planted it, little thinking that soon it would be such a formidable weed.

What is odd in Hungary is that whole stretches if it have pink flowers: like tall lilac from a distance, and interspersed with the white of elder trees indisputably pretty. I consulted Bean online (so can you. Google ‘Bean’s Trees and Shrubs’ to get to the IDS website, where the whole of ‘Bean’ is available for consultation, free). Is there such a thing as a robinia species with pink flowers? No, is the answer. There is a nursery variety, R. x ambigua (a good name) decaisneana, produced in France nearly two hundred years ago. But how could this become a widespread wildling in Eastern Europe? I must do more digging.

Meanwhile in the country at large field after field, scattered among vineyard plots, are strange orchards of elder trees on short trunks, explosions of creamy-white blossom, in long straight rows. When you see a crop repeated country-wide at random the reason is usually a government subsidy. But what can Hungary do with so many elderberries?