Upstairs in the viewing gallery, we look down on the scene. The glowing banks of orchids, gerberas and strelitzias look like flower beds visited by manic bees. Florists buzz between them, prodding petals and writing cheques. The aroma of frying bacon suddenly fills the air. "To the cafe," announces Penny, "I'm ready for a cup of coffee."
Over a toasted cheese and bacon sandwich, Penny tells me she does this flower market run twice a week on Mondays and Thursdays, driving the fifty miles here from her home near Cobham in Surrey. Sometimes she's choosing the flowers for a weekend wedding, sometimes for the plate glass foyer of a city bank or art gallery. Her floral extravaganzas appear in boardrooms and bedrooms all over London and the Home Counties. She's notched up exhibitions at the Royal Academy and flower festivals at Brompton Oratory as well as decorating the sets for BBC costume dramas.
She didn't get where she is today by sitting down on the job, however. It's 6.15 am and she's fifteen minutes late already. I bolt down the rest of my sandwich, gulp half a mug of scalding coffee and we sprint for the door. Outside in the car park Penny is loading her hatchback with today's booty. As we accelerate down Nine Elms Lane, the scent from the jungle of greenery behind us is overwhelming.
"People think this is a glamorous job," she is saying, "but there's nothing glamorous about it except the end result." Dawn is just breaking as we speed through the deserted London streets, pulling up smartly outside an ornate facade in Lincoln's Inn Fields. A brass plate announces the Association of Certified Chartered Accountants. "They like bright colours."
A few minutes later, she has swung into action. Pulling on a check overall, she unravels a black dustbin sack and snatches up broom, dustpan and brush. Bundles of pink spotted Stargazer lilies and sprays of yew fit under each arm as she scuttles up the steps. She gives the office cleaning ladies a breezy wave as we enter the hushed marble hall, gleaming with brass and polished mahogany. "Bone dry, you see!" says Penny, grabbing a handful of last week's shrivelled display in an urn in the fireplace. "They don't seem to understand that cut flowers need topping up with water. They phone me up and say 'These flowers have wilted.' "
On the other hand, if they like something, they write her a proper letter. Kneeling on the floor, Penny is yanking out the dead leaves and stems and stabbing in fresh replacements. I turn my back to study a Latin inscription on the wall and when I turn back a stunning display is already half complete. "I like a natural look - nothing too arranged," she murmurs, oblivious to this instant beauty.
Just twenty minutes after we arrived, we are sweeping up the last petals from the floor on our way out. "It doesn't do to leave any mess to annoy the cleaners," she warns, heaving a tarpaulin full of dead plants into the back of the car. We set off again. The other people it doesn't do to annoy, she adds, are the formidable matrons who usually do the flowers for the churches she decorates. "They don't like you poaching on their turf. These are powerful women, you know." Such Alan Bennett characters are only outdone by the parents of the bride at some of Penny's weddings. One such couple announced they wanted everything to be brown and cream, including the flowers and the cake. When she tried to suggest a touch of yellow, the mother had a panic attack and shrieked: "If you say the word yellow again, I shall die!"
Penny had a strict and thorough training at Constance Spry 35 years ago and would not dream of displaying such prima donna behaviour herself. The customer is always right. Even the penny-pinching father who stored all Penny's blooms for the big day in a garage overnight, and turned off the heating (in February). Next morning, everything was frostbitten, dead and brown and had to be (expensively) replaced.
"You have to be even-tempered and put up with all sorts of people," she says, as we whisk past the Natural History Museum. "It's no use having an artistic temperament. I don't even like to call myself a flower arranger. It smacks of ladies snipping rosebuds and doing dainty things with chiffon and figurines. Not me at all." Anyone who sees floristry as a slightly precious, feminine career should catch her scrubbing her hand with bleach to remove grime and sap stains or nipping between the dustbins in a dark alley dragging a Christmas tree to decorate a hard-to-find office, heaving buckets of water up ladders or jumping into an open grave to pretty up the inside with floral swags for a funeral.
Or muttering a rude word under her breath as we arrive at the V & A to find nobody about yet to let us in. With practised speed she unloads her boxes and bags near the tradesmens' entrance, signs me in and explains our mission to a selection of granite-faced guards and officials. "Really quick today," she says. "Sometimes I bang on the door for ages." Striding down the hushed corridors and deserted galleries is an eerie experience. At 7.30am in the vast marble entrance hall, only the distant hum of an electric floor polisher breaks the silence. Penny disappears to the loo and reappears lugging a huge watering can. She sets to work dismantling - and rebuilding - an impressive six foot flower tower near the cash tills. Dustbin sacks fill up with dead twigs while the Greek urn gets a fresh head-dress of giant cerise lilies, and sprays of forsythia and rhododendron leaves from Penny's own garden. There is a satisfying crunching sound as she lops the stems off a bunch of blood red amaryllis blooms and pokes them in. The floor looks like the aftermath of a shoot-out in a florist's shop.
By twenty to nine, there is a gob-smackingly impressive shellburst of crimson and gold petals, the first thing today's punters will see when they burst in. Penny narrows her eyes and stands back. "Does it look OK?" she asks sceptically. You could say that (I do). Before my words are out there is a flurry of rustling, snapping and mysterious vegetable twangs. The broom is out, the black sacks are full, Penny is back in hyperdrive. Quarter to nine sees us outside on the pavement. There is bright sunlight now and the hum of traffic on the roads.
"Right," says Penny, consulting her watch, "back down the motorway and home by nine-thirty." Not to flop on a sofa with a cup of tea and recover, though. When she arrives, a dozen Home Counties housewives, keen gardeners and/or wannabe florists (even a church flower lady or two) will be waiting for her. From ten till three-thirty she's teaching one of her day courses on the latest trends in floral art. I can't take the pace. I wave her off, with a sigh of exhaustion. Hatchback full of jungle, buckets and true grit, she turns the corner and is gone.