Enterprising English nurserymen have been going there for several years. The exchange rate may be painful if you are buying in France, but if you have something to sell, the sums become much rosier. Peter Foley from Holden Clough Nursery took over a van load of plants for the May fair and came back with very little left except some yellow rhododendrons. "They would have gone a bomb in this country," he said. "In France we couldn't shift them." On the other hand, the French had fallen upon his acers with shrieks of joy, and had hoovered up his alpines faster than he could unpack them from the van. Since the French seem happy to spend three times as much on a plant as an English gardener would, Mr Foley is planning to return, with a larger van and larger plants for the autumn show.
"Laid-back" was how he described the event. That's true, but it is the kind of laid-back that comes from attention to detail and an enormous amount of planning. Everything worked. We arrived at Courson early on Friday, after crossing on Thursday evening from Portsmouth to Le Havre. It was 2am before we drew up at the hotel in Arpajon where we had booked rooms back in March.
But just when we thought we had reached our destination, the journey turned into a surreal episode of Challenge Anneka. Stuck on the front door of the locked-up hotel was a note saying "Anna Pavord. Go to Arpajon police station". Stumbling through deserted streets in a rainstorm, we found the police station and a letter from Patrice Fustier explaining that our hotel had suddenly closed down. Hearing of this he had booked rooms for us at another hotel about 10 miles away. This seemed rather extraordinarily kind, but when I told the tale at the show the next day people shrugged. "Typical of the Fustiers", they said.
The chateau at Courson is set in a park, laid out in a way which the French call "le style Anglais", but which isn't really English at all. They choose and place their trees quite differently from us. Around the house are courtyards and barns and cart sheds with wide parkland beyond, all enclosed by stands of magnificent horse chestnuts. During the Courson Journees, stalls are laid out in the buildings, although most are in the park, either in the open or sheltered by white canvas booths.
The first thing you notice is that the French like to buy their plants BIG. Forget plastic carrier bags. Here there are porters with trollies to wheel sold plants from stalls to car. I watched one of them transferring a rhododendron in full flower to the car park. It was beautifully rootballed in sacking and at least five feet high and wide. The porter eased it over the bumpy grass more carefully than if he had been pushing his grandmother.
One woman was staggering towards the car park with a climbing rose at least 12ft tall, pink, in full flower, and swathed round with polythene sheeting. She looked as though she was about to toss the caber in some Highland Games, hands locked underneath the pot, face completely lost behind the bulk of the rose's stems. High over her shoulder, the flowers waved to passers-by.
We can do shows very well in England. We can do plant sales too. We can certainly provide settings that might match Courson. But I haven't ever been to an event in England that had the joie de vivre there seemed to be at Courson. Nor such good coffee.
The French are much keener on pruning and shaping and training trees and shrubs than we are. You notice this particularly with wisterias, which are rarely shown by English nurserymen, grown on a single stem as standards. Many of the ones on display at Courson had been grown this way, the heads beautifully pruned and balanced.
The best were at Pepiniere du Domaine des Rochettes, a Loire nursery owned by Ghislaine de Preaulx Carlo. She had standard wisterias made from not one but two stems twisted together like a rope. The effect was magic. "25 ans" said the label hanging from the double trunk, 25 years of pruning and tending and training before you even put a plant up for sale. The price tag was impressive, too: 5500 francs. But as an English nurseryman pointed out, that only represented earnings of pounds 28 a year for the wisteria's trainer.
The Domaine des Rochettes display was simple but stylish. White gravel had been laid on the grass to make a short straight path leading to a statue. Either side of the path were big pots of Acanthus mollis (340 francs each) and Hosta plantaginea, the dark bottle green foliage of the acanthus contrasting strongly with the bright, almost lime green of the young, perfectly shaped paddle leaves of the hosta. On each side of the path was a double-twist standard wisteria and ranged along the back, flanking the central statue, a line of splendid one-off rhododendrons and azaleas: `Mrs Charles Pearson', nine feet high and wide with pale pinky-mauve flowers in large cone-shaped trusses and the delicate azalea `White Swan', another 25-year-old star.
Plant names of course are the same wherever you are, botanical Latin constituting a kind of Esperanto which is as easily understood at Courson as it would be in Harrogate or Berlin. Variety names, too, stay the same. At tablissements Cayeux, the inky iris `Study in Black' did not suddenly become `tudes en Noir'.
Their stand, with some dazzling iris simply displayed (they offer 400 varieties) was next door to the peony specialist, Pivoines Riviere, the only nursery in France (according to the encyclopaedic Courson catalogue), which concentrates solely on peonies. The show is well-timed for them - as it is for iris growers. I particularly liked their dark maroon `Chocolate Soldier' with a dramatic central boss of pale stamens.
In the old stables, orchids dazzled the swallows who were trying to get on with a spot of nest-building. Spinning over the heads of the visitors, they wove in and out of the rafters like skiers on a slalom, round and round the paphiopedilums, in and out the cattleyas of Vacherot and Lecoufle - the elegant Ile-de-France nursery that filled the mangers along one whole side of the stables with their orchids. Along the other side was an antiquarian bookseller. I didn't dare look at that stand.
Through the three days of the show, the Fustiers arrange a series of lectures in French, German, English or Dutch and I went to hear Diana Grenfell, co-owner of the Apple Court Nursery in Hampshire, talk about hostas, her speciality. Before the talk, she and the Belgian breeder, Ignace van Doorslaer christened a new hosta `Domaine de Courson', a handsome beast with huge, ribbed leaves. The plant, stylishly done up in sacking and twine, held centre stage while M van Doorslaer handed round sugared almonds, just as at a real christening. And what was the hosta christened with? Champagne of course. Nothing but the best at Courson.
The next Journees des Plantes de Courson will be held from 18-20 October. The address is 91680 Courson Monteloup, France. If you are driving, it's a good idea to take your car from Portsmouth to Le Havre - you can approach Courson via Chartres and avoid the terrifying Paris peripherique. If you get to Paris by Eurostar, you can continue by train, taking the Ligne C du RER (direction Dourdan) from Paris, and getting off at Breuillet- Bruyeres le Chatel. There is a minibus shuttle service from the station to Courson, 5km away. Admission to Courson is 60 francs.
This year's European garden festivals
Holland, 14-16 June
International Specialised Nursery Festival.
Eugenie van Weede has lured nurserymen from Belgium, Britain, France and Germany as well as the Netherlands to this event at Bingerden House, Bingerdenseweg 21, 6986 CE Angerlo (near Arnhem), the first of its kind in Holland. Open Friday (2-6pm), Saturday and Sunday (10am-6pm) Admission HFL 17.50 (Tel: 00 31 313 47 22 02). This is followed (19-20 June) by a two-day symposium "Perennial Perspectives: Creative Ecology and Integral Landscape Design", which features a list of eminent speakers such as the landscape architect James van Sweden and the photographer Marijke Heuff. More details from the symposium secretariat at St Antonielaan 182, 6821 GL Arnhem, Netherlands (Fax 00 31 26 44 25 196).
France, 15 June-20 Oct
Festival International des Jardins.
The festival is held in the grounds of the Chateau de Chaumont, 41150 Chaumont-sur-Loire, 17km from Blois on the D751 to Amboise. Alternatively, travel by TGV to St-Pierre-de-Corps and change for Blois. Local trains stop at Onzain, 3km north of Chaumont. The festival is open daily from 9am-dusk. Admission is F40. It is a good idea to allow at least two hours for a visit. There are free guided tours in English throughout the day. (Tel 00 33 16 54 20 99 22).
Belgium, 4-6 Oct
Fete des Plantes et du Jardin.
Prince Antoine de Ligne holds these fetes each year on the first weekends of May and October at Les Jardins d'Aywiers, Rue de l'Abbaye 14, 1380 Lasne, Couture-Saint-Germain. Take exit 22, signposted Waterloo, from the Brussels ring road. Open Friday (2- 6pm), Saturday and Sunday (10am- 6pm) Admission F80. (Tel 00 32 633 20 21). The spring garden fair in the grounds of Courson chateau (above). The park is laid out in a way the French call `le style Anglais', but which isn't really English at all. And the flower show itself is distinctly different from such events in Britain: the French like to buy their plants big, and are much keener on pruning, shaping and training trees and shrubs