A cut above: How Ellie and Anna became experts in lacy ammi, English lilacs and witchy hellebores

The two friends set up their business, The Flower Appreciation Society, two years ago and do flowers for weddings, parties, photo shoots and restaurants. Best of all, they like English flowers, when they can get them.

I can't hold a figure as big as a trillion in my mind. The '0's keep dropping off the side and, inexplicably, turning into sheep. So when I'm told that 23 trillion cut flowers are bought every year (that's a worldwide estimate) I can only nod, hoping that at least I look as though I understand.

The worldwide trade in flowers is just one of the facets of a new exhibition at London's Garden Museum, called Floriculture: Flowers, Love and Money. Transport has been the key to the way that the market has changed. The growing demand for cut flowers in the big industrial cities of the country was neatly matched by a growth in the railways. Without the means to get their flowers to market, the bulb growers of Lincolnshire, for instance, could never have built up such a demand for their goods.

In the 1880s, JT White was one of the first local growers to get spring flowers – mostly snowdrops and daffodils such as the old cultivar 'Sir Watkyn' – into the Covent Garden market. Some were grown on his own small plot. Others were gathered from the cottage gardens of the neighbouring hamlets. But in 1899, the yellow trumpet daffodil 'King Alfred' burst upon the scene and for the next 50 years, it dominated the daffodil fields of the Fens.

Tulips only began to be grown in any quantity after 1907, when another pioneer, Frederick Culpin, bought from Holland a hundred bulbs of the new, strong, showy Darwin tulips bred by the Dutch grower E H Krelage. The beautiful pink flower 'Clara Butt' was among them; so was 'Pride of Haarlem', a brilliant cherry red. Both could be forced to provide flowers for the lucrative early markets.

Nobody then thought of cutting flowers in bud. Sellers thought they would not make enough of a show to tempt buyers. Only in the 1960s did Carlo Naef, of the Covent Garden firm J & E Page, singlehandedly persuade customers that by buying daffodils and tulips in bud, they were getting flowers that would last longer in a vase.

The cut-flower business was still then a mostly local affair, but in 1969, the first air-freighted flowers touched down in New York, sent from growers in Colombia. As international trade boomed, local growers went out of business. Once, 10,000 acres of the Fens were devoted to growing flowers. Now it's just 300 acres.

But in a flower-filled workshop in north London, smelling of green, 30-year-old Ellie Jauncey and 31-year-old Anna Day dream of recreating a market for local flowers, perhaps getting allotment holders to grow special things for them. They set up their business, The Flower Appreciation Society, two years ago and do flowers for weddings and parties and photo shoots and restaurants. Best of all, they like English flowers, when they can get them. "Mondays and Thursdays are the days we go to the big Nine Elms flower market," they explain, "because that's when all the English stuff comes in. We're not into the tropical look."

I happened to call on them on a Thursday and the floor of the workshop was covered in fresh flowers and greenery. There were huge swags of ivy and rosemary, big branches of catkins, and, most astonishing to me, even bigger branches of magnolia all in furry bud.

Never before, in England, have I seen magnolia cut like this. I first saw it in America, where in early spring, huge vases of it decorate places like the Metropolitan Museum in New York. I have a particular reason to remember vases of magnolia in America, because when I was speaking at an event there, in front of hundreds of people, I stepped backwards to look at the screen behind me, and fell off the stage right into the middle of a magnolia-filled urn. I wanted to stay there forever.

In Ellie and Anna's workshop, hellebores were the great prize snatched from the flower market early that morning. Who on earth is growing enough of those to be able to cut them with such abandon, I wondered? And who was going to be lucky enough to have them included in one of the luscious arrangements that are the girls' speciality? That morning, they'd even found some roses with a scent, each bloom wrapped in a protective net, like a small crocheted shawl. They had bunches of long-stemmed astrantia, lacy ammi, even some phlox. No lilies. Ellie doesn't like lilies. Especially not with the stamens cut out.

That got Anna talking about a year-long floristry course she did a while ago. "Horrible. So manipulative. Folding leaves. Putting a fake diamond in the middle of a rose." Ellie joins in: "We just want to use our flowers in as natural a way as possible. A lot of it is about selecting colours. We've got a lot more confident about that."

The business started by accident when they were both working in The Scolt Head pub up the road. Anna (who trained as an illustrator) had promised to do a wedding. Ellie (who as a student studied textiles) helped her, using flowers bought from the Sunday-morning market in Columbia Road. Then the landlady of the pub gave them a contract to keep the place decorated. They splashed out on a camera. They set up a website (theflowerappreciationsociety.co.uk).

And they started going to the big wholesale market at Nine Elms. "We love the market," says Ellie. "It's dark, it's freezing cold, but when we get there, it just makes you feel happy. The guys we buy from are so brilliant." "And you come away feeling so much better than when you arrived," adds Anna. "It helps that we don't have a shop. So we can get there about six in the morning, relatively late."

Anemones, ranunculus and the witchy hellebores are top favourites this season. "But the lovely thing about flowers is that there's always something to look forward to," says Ellie. "English lilac," says Anna. "English lilac," says Ellie. And we all sit there in the lovely workshop, surrounded by the soft green smell of flowers, dreaming of a day that will not be wet and windy and wintery and wild. A day when English lilac first comes into season.

Meanwhile, there's St Valentine's Day and from the 12 to 14 February, Ellie and Anna will be selling from a pop-up shop at Boxpark (a collection of freight containers) in Shoreditch. Look for Unit 17. To order flowers, call Ellie on 07980 270658.

The exhibition at The Garden Museum, Lambeth Palace Road, London SE1, starts on 14 February and continues until 28 April. It's open Sunday to Friday (10.30am-5pm) and Saturday (10.30am-4pm), admission £7.50. For more information call 020-7401 8865 or go to gardenmuseum.org