Hot  tropics: Emma Townshend meets a Brazilian with a fiery passion for bromeliads

Oh, bromeliads will be my madness, even when I get old,' says Marcelo Sellaro, finding, even in a foreign language, an evocative phrase to convey his life's passion. 'But, at least it will be a healthy madness.' He is the Brazilian in charge of Kew Gardens' bromeliad collection, many of which came from the South American rainforest, just like Sellaro.

Bromeliads are sometimes considered to be the orphan cousins of the tropical-flower world, looking too plasticky and weird to inspire true plant love. They have suffered from being closely associated with the 1970s, having appeared on bits of driftwood on one too many Californian-style porches. But if we could just stop seeing them as odd, and out-of-date, and start to appreciate their strange beauty, we'd be so much better off. 'For me,' says Sellaro, 'they represent the Brazilian wilderness. I feel so frustrated, because shops only sell hybrids, and there are so many beautiful species that they could be offering.'

It's a complaint you often hear from orchid enthusiasts too. But now Kew Gardens is giving us all the chance to widen our horizons, with its annual orchid festival that this year is bigger and more exotic than ever before. The Princess of Wales Conservatory is being transformed into a bustling centre of activity, and a one-stop celebration of tropical flowers - including masses of bromeliads.

There are plants there that are so new that their classification is still being worked on; they were brought back from Brazil only this year, after Sellaro and his colleague Lara Jewitt went hunting for them. It's thrilling to see plants so new to human study that there's a blank space on the label where the species name will eventually be. Many are donations from a Brazilian expert, the wonderfully named Elton Leme, who combines a career as a high-court judge with a part-time bromeliad habit.

In idiosyncratic English, tinged with a strong Portuguese accent, Sellaro gives an energetic account of his own progress from the tropics to the grey skies of west London and back again. His first specimens were grown in a corridor at his childhood home, and he still struggles with the perils of domestic cultivation: 'Here at Kew, our plants grow on bark, and are hung on the wall. But you can't do that at home, because you can't mist your wall, as the wallpaper gets damp.' We can only hope he didn't find that out by experiment, just for his mum's sake.

The constant watering is necessary because, like orchids, many bromeliads are epiphytes; that's the technical word to describe hitching a ride for life on a tree, or other perch - some epiphytes manage with the very minimal comfort of a single telegraph wire. They anchor themselves in a safe corner with gluey roots, but the water and nutrients that would normally come up from the soil, come from above instead - a life lived on permanent trickle-down. Bromeliads have all kinds of special adaptations to make sure they make the most of any rain or mist in the air: like little blotting-paper-ish cells on their leaves that suck in airborne moisture with beauty and efficiency. But in the absence of roots, when we grow them at home, that wallpaper-wrecking spray is vital.

But what about those of us who leave the festival wanting to try growing these exotics at home? One of the complaints I've often read about bromeliads is simply that they die after they flower. 'It is going to stimulate your horticultural skills,' says Sellaro, 'because the plant always offsets.' The offset is the new group of leaves, essentially a whole new plant, growing alongside the main flowering plant. He quickly removes one from an Aechmea lying on his worktable, using a sharp knife, 'If you are going to plant into soil, maybe leave it for a day, to harden over, so it doesn't get fungi and bacteria into the wound. Only then plant it in compost.'

He has great faith in the robust qualities of these plants, even though he admits that it's not always easy. 'My friends say, 'I got a bromeliad, but it died.' It's hard, because sometimes even my bromeliads die... ' His advice is to pick the tougher plants - like Guzmania, Vriesea, and the Nidulariums - that will survive in lower light levels, and to keep humidity as high as you can. A nice light bathroom window seems like a good idea (and at least then you don't have to get into trouble for misting any wallpaper). Frustratingly, you will be hard-pressed to find named species sold anywhere in the UK - though plant stalls, flower shops, and supermarkets will almost always have a couple of hybrids in stock.

My own favourite is the one I was already growing and didn't know was a bromeliad; Puya chilensis, is one of the nastiest, yet most elegant plants in my back garden, and now I finally get to see how it fits into the whole scheme of things botanically. More than that, while reading up on my Puya, I got to freak out over pictures of its bigger relative, the Puya raimondii, which lays claim to having the biggest flower spike in the world, sometimes growing to a height of 12 metres. Please Google it now. The last word, though, belongs to Marcello. What is his favourite bromeliad? 'Oh, I couldn't say!' He thinks for a minute. Then, pointing to Aechmea fasciata, he reflects, 'Well perhaps this one, the first one I ever grew. And it is the one I got a picture of, for my first tattoo.' Tattoo? Tattoo! What brilliant, infectious, thoroughly Brazilian madness.

'Intensely Tropical', Tropical Flower and Orchid Festival, 3 February-4 March, Royal Botanic Gardens, Kew (tel: 020 8332 5655; www.kew.org )

If you do one thing this week

Buy snowdrops

Now is the time to plant snowdrops 'in the green', ie, while they are in the leafy stage of their life cycle, ready for next year. Make sure you space them out a bit, so they have room to grow. This winter has been such a non-event, that it's difficult to feel impressed with the first bulbs of spring. But with luck, next year's January will be really cold, and when you look out at those delicate little white stems, you'll thank yourself.

Q&A

Emma answers your horticultural queries

My Lantana dies whenever I go away, because my housemate fails to water it. What should I do?

Tim Henley

It's important to prepare properly: soak your plants overnight before you go in a full sink of water; this will work much better than watering them from above. Move them out of the sun - no point drying them up unnecessarily. If you are away for a long time, consider replanting the Lantanas with water-retaining gel in their compost, like Rain Gel Drought Buster Granules, or Swell Gel.

Horrors! Something is eating my rosemary bush. What can I do?

K Smart

The culprit is almost certainly a pest new to Britain, but spreading fast: the rosemary beetle. The beetles themselves appear in spring, and are a metallic green and purple. The larvae eat the plants too, and they are more grey and slug-like. Whatever the appearance, they all need to die. First, shake the bush on to newspaper and tie whatever falls out straight up into a binliner. Then, squish as many critters as you can find. Finally, turn over the soil under the bush, because at this time of year the larvae are pupating, so it's possible you'll expose a few to natural predators that way.

If the bush isn't one you use for eating, you can go chemical, perhaps with Ultimate Bug Killer. If you do eat it, use an organic solution such as Py Garden Insect Killer. Think carefully, though; my rosemary got eaten because I didn't want to kill all the little moths and bees that live on it.

You'll have to keep an eye on your plant from now on, and on related plants such as lavender, sage and thyme. There's no point eradicating them from one to find another is infested .