Gardening: Life under glass in a cold climate: Anna Pavord seeks expert advice to turn the conservatory of her dreams into a reality

It is fantasy time again. The dispiriting reality of November's gales and rain fosters extravagant dreams. Mine, as always, centre around a conservatory, a leafy, scented, luxurious bolt hole that I can escape into as the wind howls down the chimneys of the house and the rain beats down the last remnants of chrysanthemums in the garden.

A fantasy conservatory is far easier to manage than the real thing. Whitefly, red spider mite, scale insect and heating bills have no role to play. And the space that you play with in your mind is always more elastic than the real thing could ever be.

Feeding the fantasy requires regular forays to other people's conservatories. At the National Trust garden at Wallington in Northumbria, there is a splendid old lean-to conservatory.

When frost had brought the flowers outside to a standstill, plumbago was still rampaging up the pillars inside and fuchsias, in enormous glazed pots, were dripping with flowers. Smaller clay pots, filled with a vast array of flowering plants, were clustered together on the flat workbench that ran along under the lowest side of the building.

I would want doors at either end of my conservatory and a working area divided from the main space where I could rest plants and bring others on to put in the display house in season. The floor would be stone or unglazed terracotta tiles, something that could be sloshed over fairly regularly with water.

Shading would be a problem, as most new conservatory owners find out in their first summer of occupation. Blinds are a common option. That would be too domestic for the conservatory I have in mind. I think I would experiment with reeded glass - if I could get hold of it - and also train vines along the ribs of the roof to provide shade. The advantage of vines is that they drop their leaves in winter, when the conservatory needs maximum light.

The disadvantage of vines, according to Lisa Rawley, whom I met this week on a different sort of conservatory foray, is that no one has yet invented one that is proof against mildew. Spraying an indoor overhead vine would be a pretty horrible job.

Ms Rawley is the founder and sole proprietor of Fleur de Lys. She provides plants for conservatories and, more importantly, offers continuing advice and support for despairing conservatory owners.

The key to running a successful conservatory lies in choosing the right plants, she says. That seems a simple enough message, but it is one that many people have been slow to grasp.

Most conservatories, she says, ignoring my vision of a damp, rather cool planthouse with perhaps an odd, concessionary rattan chair or two, are small, hot, dry, fully furnished and with the sort of floor that their owners do not want to see permanently running with water.

These conditions most closely approximate a hot, dry Mediterranean climate. But the plants seen as suitable for conservatories are usually leafy specimens from the tropics, where humidity is always high and winter and summer temperatures differ little.

Laden with luscious photographs of mimosa, olive trees, citrus of various kinds, hibiscus, bougainvillaea and pandorea, all taken in her working greenhouse at home, Ms Rawley visits prospective clients to explain what plants are best for their particular situation.

Once the plants are installed, she will, if necessary, make regular visits to titivate, prune and train them, or do whatever else she thinks is necessary. August is the busiest month for this sort of follow-on work. 'It's when bugs are at their worst. People panic when they see clouds of whitefly rising off their climbers and their orange trees covered in red spider,' she says.

The problem can be solved with a little forethought in May. This is the time to introduce predators that will keep on top of most pests.

Whitefly, the most difficult to eradicate, is an ancient enemy of Lisa Rawley's. Before she started Fleur de Lys, she worked as a horticultural adviser with the Farm Advisory Services Team, specialising in fruit. Did she miss that job? 'Only the pruning,' she says. 'I really loved pruning.'

What that job did not have is the imaginative element that she enjoys in Fleur de Lys. Everyone has different ideas about how they want their conservatory to look, and she likes the challenge of turning ideas into reality.

She recommends climbers for most conservatories. Floor space is usually limited and few modern conservatories have proper greenhouse borders (although passion flowers do much better planted in borders than in pots).

Stephanotis is a favourite and is evergreen, a huge advantage in a conservatory. If it were perfect, the white, waxy flowers would come in winter, rather than summer, for there is plenty else to be sniffing at between May and October. Plants will grow to 10ft or more, so they need to be trained and tied in as they grow. This is not a Mediterranean plant and needs a winter temperature of about 50F.

Ms Rawley also uses the primrose jasmine, J. mesnyi, which is evergreen and has semi-double flowers, much bigger than our winter jasmine. They bloom from March until May. It needs hard pruning when the display is over. Cut out all the branches that have flowered and tie the new growths into wires or other supports.

This is something that needs to be remembered when thinking about the placement of plants in a conservatory. All climbers look better if they are properly trained rather than bundled into a lump and hitched over the nearest projection. The best time to fit supports for wires is when the conservatory is being built.

Correct watering is also critical. Ms Rawley likes to set pots standing on trays spread with at least 3in of Hortag. This is a clay aggregate, made up into small round pebbles, which absorbs moisture and keeps the atmosphere around growing plants suitably humid. It also saves the plant from the perils of over-watering.

Over the past three years, Ms Rawley has been building up a list of reliable plants. Clerodendrum thomsoniae, an evergreen climber with red and white lantern flowers, has been struck off the list. 'Too tricky in winter,' she says. 'It needs a high temperature and humidity.'

Palms do not always behave themselves either. 'They don't really like full sunshine, which is not what you would expect.' Bougainvillaea is a star, but needs a big tub, a foot across at least, to grow properly. Ms Rawley advises her customers to be brave and pull off the first flowers that show in spring. 'It has a dramatic effect on the later show. When the next lot of flowers come on in July, they will then go on for months.'

The mimosas were in flower in the greenhouse where Ms Rawley keeps her stock plants. I would be very tempted by these if I had a big enough space in a conservatory. But they grow fast and it would be a pity to have to chop them about too ruthlessly.

I thought the variety she had, 'Mirandole', was better than the ordinary mimosa, Acacia dealbata. The foliage was more interesting, not feathery, but almost spiky and an arresting metallic grey colour. It was already flowering, the first flush carrying nicely through the winter. This is followed by a second flush in mid-summer. Mimosa needs a winter temperature of only 40F and positively enjoys dry conditions.

Mimosas, with their wonderfully cheering flowers, would contrast well with various types of oranges and lemons in tubs. These also have the advantage of being at their best in winter, the ripening fruits hanging among the waxy blossom that will eventually become next year's crop.

The showiest citrus I saw at Fleur de Lys were fat bushy calamondins with variegated foliage, hung all over with small round orange fruit. I thought they were enchanting. They never get more than about 2ft tall, but need pinching back at regular intervals to keep them compact and bushy.

For the best effect, you would need a grove of citrus, a potted grove, the stubby calamondins interspersed with taller Meyer's lemons, grown as standards. Their sober, glossy foliage would cool the calamondins down. The pale fruit looks stupendous. I fancy one as a centrepiece for a Christmas dinner table. It will feed the dreams until a real conservatory comes along.

Fleur de Lys is at Kemsdale House, Hernhill, Faversham, Kent (0227 751297). Lisa Rawley charges pounds 35 for an introductory visit, redeemable on plant orders over pounds 200. Climbers (5ft-6ft) cost from pounds 18-pounds 25, trees pounds 35. No mail order. Conservatory maintenance work at pounds 18 an hour.

(Photograph omitted)