A meadow at the Butterfly World site, near St Albans

Wildflower meadows sound so attractive and gardeners have been seduced into trying them by dreamy photos of all those lovely butterflies hovering over them in midsummer. I wonder how many owners have been disappointed.

These meadows are quite a business to mow and maintain. Some of their components swamp the others and by August they can look an awful mess. If well run they have their spectacular moments but on any serious scale they require a thoughtful investment in machinery and labour and a plan for disposing of masses of greenery when the mowing season eventually begins.

I am also at odds with one of the dominant models. It limits the residents in the meadow to British wildflowers only and encourages us to “recreate the wildflowers of our childhood”. My early memories are of stinging nettles and thistles. The best wildflowers in my early years were in the soppy coloured pictures in Alison Uttley’s books about Little Grey Rabbit. I am not thinking, either, of the picture of Fuzzypeg the Hedgehog smoking drugs in a ditch among flowers in an English hedgerow.

What I have longed to see is a very different recreation from my youth, a mini-meadow of all the lovely annual flowers from around the world. In the school holidays I used to look after just such an annual border on a modest scale. The haze of clarkia, godetia and cornflowers was far more lovely than the tangle of dock-leaves, fat hen and groundsel in “nature” beyond our garden wall.

I have tried half-heartedly to recreate this look by scattering seed of mixed annuals on bare soil in outlying parts of the garden. I have had some spectacular shows of mixed calendula and some blue cornflowers and Turkish Agrostemma Milo that have been happy to be multicultural neighbours. One day, I tell myself, I will get on top of this game.

A supplier kindly sent me a sample of a seed mixture that would recreate a wildflower lawn if I simply tried to “throw and sow”. Unfortunately I left it near my desk in my Oxford college library and some keen young sower pinched it during the lunch hour. Plainly the seeds did not live up to expectations because I found half of them two days later in the rubbish bin of the library’s psychology section.

Clive Farrell, the garden’s creator

By now you see how excited I have been by news and promotional pictures of a huge new sowing of non-native annuals just within reach of the M25 and M1 motorways and the London North Orbital Road. It takes a lot to coax me over to a building site between three traffic jams on a summer Saturday but my recent visit was better, even, than anticipated. At Chiswell Green near St Albans annuals have been flowering their heads off on the emerging site of Butterfly World. I last visited to see the National Rose Society show gardens, then at a peak of hectic modern colour. Since then the society has had its financial struggles, only to be rescued by the property entrepreneur and apostle of “butterfly gardening” Clive Farrell. He has retained use of the outlying acres on the wilder edges of the society’s show grounds. His aim is to turn them into the butterfly display of all times.

I admire Farrell’s nerve and vision. Acres of ground have already been reshaped and reseeded as part of a three-year plan. Meanwhile, contemporary designers have laid out Future Gardens in varying styles of experimental wit. Even the public lavatories by the entrance are designed in the shape of modern beehives. The designer-in-chief, Ivan Hicks, proudly showed me the wall of his own garden section. I was shocked at first to see books with open pages built into a wall of jumble and set only a metre or so away from a sculpture of the backsides of the naked Three Graces. “The books are for garden-bookworms,” Hicks explained, and I softened when I saw that they were old useless texts of English mortgage and banking statutes. The Graces’ rear view will encourage any unfortunate readers.

Farrell’s ambition is to install a grand dome in which tropical butterflies of the world will be fluttering happily in the Olympic year of 2012. His team has built the foundations and is looking for investing partners who will put in the £12m needed to attract up to 1m paying visitors a year. I hope there are people out there who will catch the spirit of this venture and invest in the Butterfly Olympics, which will be so much prettier than the imminent athletic nightmare. Outside, big drifts of wildflowers will coil round the paths in the shape of a butterfly’s antennae. Here the first year has been devoted to global annuals, “hydroseeded” into the soil by water pressure from a hose. In flower they have been a fine sight. I looked across banks of my childhood favourites, contrived by stirring up 100kg of seed mixtures, many of them from the US.

Yellow coreopsis, pink clarkia, blue cornflowers, fine pink lavatera and masses of coloured layia have made a pattern across 27 acres that leaves a “native English meadow” of white ox-eye daisies and purple knapweed looking as second-rate as the English seaside in August. Where, though, were the weeds?

In preparation for hydroseeding the gardeners had turned normal practices upside down. With machines they had buried all the topsoil 5ft below the surface and left only the poor subsoil in which simple annuals, but not nettles, will grow. Somehow the sight of this upside down gardening hurts my prejudices when I see it. It certainly keeps out weeds and restrains annuals to a modest height. It makes excellent sense if you want an annual meadow but it will distress future generations if they ever want anything else.

I remembered Farrell’s earlier book The Butterfly Gardener, co-written in the 1980s with the indomitable Miriam Rothschild. Up on her Northamptonshire estate Dame Miriam had set about wildflower gardening and seed-production on an industrial scale. Her son is still trying to unload the surplus harvest that she grew for her famous Farmers Nightmare seed-range. What ever would this early apostle of the art think of her protégé Farrell’s latest gigantic ambition? I called her to mind, wearing her trademark white gumboots and typically berating me for my “childish” attitude to wildlife as she showed me the tame foxes in her fruitcages and tried to talk me out of my lifelong love of foxhunting. As I remembered her own not-so-youthful fondness for the sport, I vowed not to give it up.

Lo and behold, in the centre of Farrell’s annual-flowered extravaganza stand a pair of white gumboots, specially cast in concrete as a homage to Rothschild, Farrell’s continuing inspiration.

At 6pm on a sunny Saturday evening the only things missing were the butterflies. Not one of any interest was to be seen in the acres of international annuals. I like to think they were off watching the Ashes test match. Alternatively their great scientific student Rothschild had called them away for an evening meal in another meadow in the sky.