Shady character: All hail the mighty fern

For looks, you could not do better: tall, elegant, formally and soberly suited but without a hint of stuffiness. Interested? You should be. If you have not made a date with Dryopteris wallichiana, get going now. Admittedly, the name is a stumbling block and when you meet this paragon, you'll realise that Wally isn't an option.

For the whole of May, I've been mesmerised by the slow, Zen unfurling of the ferns in our garden, but Wallich's fern (it's named for Nathaniel Wallich who was superintendent of the Calcutta Botanic Garden in the 1830s) has a touch of menace about it that makes it unforgettable. The fronds start off, like most ferns, as tightly clenched fists, crouched together on the ground. They unfurl and lengthen very slowly – the process takes at least five weeks – looking towards the end like a series of shepherds' crooks, the tips making an elegant double downward curve.

The menace comes from the hair covering the backs of the stems, so thick it looks like monkey's fur. It turns the whole thing into something more like an animal than a plant. When the fern is fully unfolded, you notice the fur less, because like most ferns they arch outwards into a vase shape. By this time it's about 120cm (4ft) tall, a brilliant, scintillating green. Although the green settles, as all greens do, into a duller shade by August, the elegant form remains, a superb foil then for lilies, that just now are little more than snouts above the ground.

I've yet to meet a fern I didn't like. They were early arrivals on the world scene and have the easy, pared-down grace of plants with 400 million years of breeding behind them. In the wild, D. wallichiana has been found in Hawaii, Mexico, Jamaica – and the Himalayas, which must have been where Dr Wallich first saw it. Another fern buff, Christopher Fraser-Jenkins, who has written a book about the dryopteris of India, recently found it again near Darjeeling.

At the time of Wallich's death in 1854, the fern craze in Britain was at its height. Great collections were made and then, on 22 September 1891, at Mr Wiper's Rooms, Kendal, Cumbria, the first members of the British Pteridological Society gathered together to swap specimens.

Their story is told in a superb new book, Fern Fever (Frances Lincoln £35) by Sarah Whittingham, who asks, as other fern fanatics have before her, why so many brilliant variants of British ferns were found in the Victorian age but have never been found since. Over-collecting was probably one cause. But she thinks, too, that many of these oddities, called 'sports', came about because of environmental differences in soil, aspect and humidity. "Sports that were collected were often propagated and distributed, so preserving these changes, while plants left in the wild eventually reverted to their original parental form," she writes.

Yes, perhaps so. But if sports revert in the wild, you'd think that they would in gardens, too. And they don't seem to. Take 'Bevis'. Or Polystichum setiferum 'Pulcherrimum Bevis' as we're supposed to call it (see what I mean about the names?). Polystichums are a huge family, and are among the most common of our native ferns, with fronds that stand green all through the winter, until they are replaced by the new brood uncurling from the centre of the clump.

'Bevis' was collected in 1876 near Axminster by an agricultural labourer called Mr Bevis, who was employed to cut back the hedgebanks in the narrow Devon lanes. He noticed that the fronds of this particular polystichum were finer than usual, with the individual frondlets sweeping up towards the tip in an unusual way. He took it to a local collector, John Wills, a doctor at Thorncombe, near Chard, who thought it one of the best 'sports' he had ever seen. But it's never been seen since.

You can split crowns of 'Bevis', in the way that you might with a clump of Michaelmas daisies. But it's a slow process, as ferns sensibly don't do fast, which meant 'Bevis' was always expensive to buy. Now, thanks to the miracle of micropropagation, you can pick them up for about £8. They're said to do best in a well-drained site in shade, but I've got them in several different situations and they seem to motor on as happily in sun as in shade. But none of the sites is dry. That's important.

Wherever ferns are, you need to allow room for the fronds to uncurl. I had three clumps under the arching branches of white-flowered Rubus tridel 'Benenden'. For a while, the combination worked fine, until the weight of the rubus's branches brought them too close to the tops of the ferns. That was easy to solve; I sawed off the offending branches of the shrub. Rubus, anyway, needs this kind of treatment.

Otherwise, ferns need very little attention. Many of the most common garden ones are evergreen, in the sense that hellebores are evergreen. When the new leaves start to show, you need to get rid of the old battered ones, so you get the full advantage of this fresh, late-spring eruption. With the lacy maidenhair fern, Adiantum venustum, the job is best done by February. Then you can shear over whole clumps without fear of harming the fine, fragile growths of the new fronds.

Ferns are ideal plants for town gardens, where their elegant green fronds provide the most soothing antidote to brick and tarmac. They are particularly useful in shady areas, such as the narrow passage which so often runs along the side boundary of a terraced house. Hart's tongues (Asplenium scolopendrium) with their shiny strap-shaped leaves, make a good contrast with lacier types such as the lady fern, Athyrium filix-femina, mixed perhaps with epimediums and perhaps some colchicums to give the border a boost in autumn. For a cool, ever-pleasing effect, you'll need little else.