The first orchid festival at Kew took place last year, and was devised as a one-off. It proved so popular it is to be an annual event for at least the next three years. The lectures taking place next week are over- subscribed; even on a freezing March weekday, the exhibition in the Princess of Wales Conservatory was seething with enthusiasts armed with sketchpads and cameras, murmuring "Wonderful ... splendid ... the colours! The shapes!"
Sandra Bell is manager of the orchid unit at Kew. "Once bitten, most people become excessively interested in orchids," she warned in her introduction to the seminar. "It's an unfortunate phenomenon, but it does happen. So if you're teetering on the brink, be very careful." It was already too late, however, for the 54 orchidophiles gathered in the state-of-the-art Jodrell Lecture Theatre at Kew. They had come from as far afield as the Midlands and Cambridge, in "suitable weatherproof clothing and appropriate footwear" (as recommended in the brochure for the short stroll from the lecture theatre to the conservatory).
Joan had brought a flowerless specimen nestling in a basket for an expert diagnosis. Bill, a professional gardener, had braved the Underground for the very first time to discover how to set up an orchid collection in the Victorian glasshouses he was restoring ("I'm a bit thick about this. I don't really know how I'm going to find my way back," he sighed, poring over his Tube map.)
Sandra began by whetting everyone's appetites with a few seductive slides. "This dendrobium from Thailand is like a waterfall of gold cascading out of a tree," she observed. There was a collective sigh of ecstasy. "The largest south-east Asian rainforest types can grow stems 50ft long with no difficulty - its weight can cause the tree it grows on to fall over. As for the smallest, you could fit hundreds of flowers on the average person's thumbnail." A huge thumb surrounded by exquisite, tiny flowerlets appeared on the screen.
Orchids, as well as being tougher than they seem, are also sneaky little things. "They are specialised exploiters of insects," explained Sandra affectionately. "One woodland orchid's nectar ferments to provide the pollinating wasps with alcohol as they climb the stalk. When they reach the top they're in no condition to fly too far, so they end up at a neighbouring plant and spread the pollen when they start crawling up it, getting ever drunker."
There was barely a cough from the mesmerised audience, as Sandra guided us through a selection of orchids: delicate lacy ones, hairy ones, some that looked like bees or butterflies, others like fat little spiders clinging to their stems, a tender tendrilly mauve one called the Naked Man and a frothy extravaganza, the Frilly Knicker Plant.
Then it was time for half the group to get to grips with a pot-bound cymbidium, while the other half trooped off to the conservatory to see the exhibition of real specimens. The Princess of Wales glasshouse is always impressive; the orchid display is little short of spectacular. There was a general gasp as we walked in. The orchids are in dense borders and baskets suspended from the ceiling. They have been arranged in clumps attached to trees and branches and lianas as they are in the tropical forests, in great swathes of yellow and pink and cream and mauve. There was also a blast of warmth, and heady scent - not from the orchids, but from strategically planted hyacinths. Though they are irresistible to insects, few of the orchids on display have a smell detectable to the human nose.
"To make it as authentic as possible, we've planted bromeliads as well," said our guide. "Orchids naturally position themselves above bromeliads to take advantage of the evaporating water from the bromeliads' cups."
"Aha," muttered someone. "That's why the dendrobium did okay - it was over the sink."
After lunch, we cantered rapidly through Pests and Diseases (orchids are particularly susceptible to sunburn). Conservation is an important part of the unit's work. "When they were constructing the Channel Tunnel Link, the contractors brought us a cubic metre of clay with a rare species in it," recalled Sandra. "They said they were sorry for cutting through some of its roots. They evidently weren't botanists: the roots they'd cut through were from an oak tree."
But the most exciting part of the afternoon was devoted to propagation. Raising orchids from seed is a difficult business, best carried out in laboratories. The home grower is better off buying a test-tube baby - a miniature plant in a glass flask, sitting in a nutrient agar jelly. These can be potted on and will become a mature plant in anything from 18 months to five years.
One of the orchid team explained in great detail how she had kept her baby plants in an old fish tank in the spare room until (much to her husband's alarm) they had virtually taken over her home. "I bought this little heating pad to get them off to a good start," she said, "then this little propagator, then this bigger propagator ... the next step is a greenhouse. Then after that, of course, two greenhouses."
Nobody in the audience thought this in the least bit strange. After all, once you have one orchid, you're going to want a whole greenhouse full.
Seminars at Kew during the Orchid Festival cost pounds 20 (concessions, pounds 15). Enquiries, 0181 332 5622. The festival runs until Sunday 31 March.
TENDER LOVING CARE FOR ORCHIDS
Orchids have something of a reputation for being delicate and difficult to rear. Choose them with care, however, making sure you pick a species that is suited to the conditions in your home, and your orchids will flower for many years. A cymbidium, for example, will last "a lifetime", according to Kew orchid unit staff.
SUPPLIERS: During the orchid festival, a wide variety of species are available to buy at Kew Gardens' Victoria Gate Shop. (An extensive range of books on orchid culture is also available all year round.) Alternatively, contact the British Orchid Council for details of your nearest orchid society or association, plus a list of reputable growers. Write to: Mr P Hunt, British Orchid Council Secretary, PO Box 1072, Frome, Somerset BA11 5NY.
VARIETIES: There are 25,000 natural species of orchid, and 100,000 man- made hybrids. Beginners are advised to start with hybrids - orchids are very narrowly adapted to their environment, and a hybrid with two different parents doubles the range of conditions it can tolerate.
TEMPERATURE: The first vital factor is the temperature of the room where your orchid is to live. When choosing, take the lowest night-time temperature into account. If you can maintain a minimum of 15 degrees you can grow orchids from warmer climates - slipper and moth orchids (paphiopedilum and phalaenopsis). These need humidity as well as warmth, so don't stand them above a radiator - keep them well away from direct heat and stand them on moist pebbles or capillary matting (do not allow to stand in water). If you can maintain a minimum of 11 degrees, choose a cloud-forest orchid that is adapted to cooler temperatures - perhaps a miltonia, a vuystekeara or an odontocidium. These require more light as well as a cooler environment - a cool windowsill is ideal. For a cool, light balcony or garden, choose a cymbidium. These should be kept indoors from September to May, but for the rest of the year will prefer to be outside. Cymbidiums often sulkily refuse to flower and in 99 cases out of 100 this is because they are not experiencing a wide enough range of temperature in the day - they need to get cool at night in the summer to encourage flowering. "If you want a phalaenopsis and you're not prepared to heat your home, or a cymbidium when you've just had central heating put in, you've got a problem," says Sandra Bell. "It's much easier to think first, rather than attempt to modify your entire life around your orchid. And while most of us might like to visit a rainforest, we don't want to live in one."
WATERING: Always water from the top; any decaying matter in the bottom of the pot will be pushed upwards into the roots if you water from the bottom, but be flushed out by top watering. Give the plant a good deluge but don't leave it to stand in water. It needs more when the compost is dry to about halfway down the pot. Use rainwater if possible, or tap water. "Orchids like quantity not quality, so don't use Perrier - it has been known," says Sandra Bell. "People love their orchids and want the best for them, but in fact mineral waters have far too many dissolved salts in them."
FEEDING: Feed your plant every other watering, with a proprietory orchid food or houseplant fertiliser at one-tenth the recommended dilution. Orchids naturally occur on poor soils and do not thrive on rich feeds. Feed relatively heavily if you water your plant with rainwater rather than tap water, as rainwater has fewer minerals. Feed only when the plant is in growth. ("How do you tell?" asked one novice. "The plant is getting bigger," said Sandra patiently.) They take a rest after flowering.Reuse content