Any colour you like, so long as it's black: Anna McKane meets gardeners who are concentrating on the darker side of plant life

GROWING black flowers seems rather a racy thing to do, like sleeping in satin sheets or wearing fishnet stockings. But black flowers, leaves or berries do provide a foil for other colours in the garden, and they are different.

Many of the names of black flowers are anything but exciting: the 'Widow Iris', and the geranium called 'Mourning Widow' sound dreary, while the 'black grass' Ophiopogon planiscapus nigrescens is impossible to remember. Ten years ago this plant, which is a relative of the lily, was to be seen in only the most esoteric borders; now its clumps of liquorice-like leaves are all over the place. It is easy to grow, and its leaves really are black, as are the fruits which follow the mauve flowers. Because it is low-growing, it needs to be planted next to something contrasting, perhaps pale blue or lemon violas.

The easiest black flowers to find are among the pansies and violas. They, like the ophiopogon, would look smart in terracotta pots on a white-walled patio. 'Black King' is the darkest large-flowered pansy and there are several blacks among the smaller flowered violas. 'Bowles' Black' has a slightly blue tinge, 'Black Panther' is a matt black, while the blackest is 'Molly Sanderson', which appeared as a chance seedling in that lady's garden in Ireland.

Jenny Bunn decided on black and white for a new 3ft-deep border against a high wall in her garden in north London. The wall was painted white, a white trellis was fixed to it and less than a year ago Mrs Bunn began to hunt for plants. Blackberry 'Oregon Thornless' spreads its ferny foliage up the wall, and two buddleias - 'Black Knight', which is almost black, and B fallowiana alba, which is white - arch forward. White flowers were easy - campanulas, clematis and plenty of bulbs - but Mrs Bunn has also found several which are white with a black eye, including the rock rose Halimocistus wintonensis, a poppy, 'Perry's White', and a delphinium.

Amazingly, in one season Mrs Bunn has found more than 20 black-flowered or black-leaved plants and the search is by no means over. Of course, black has been interpreted to mean dark purple or brown, and there is plenty of green foliage around, too, so the border does not look like a chessboard.

The daisy flowers of Cosmos atrosanguineus are almost black with a distinctive chocolate scent. Geranium phaeum, the 'Mourning Widow', is very dark, as is Veratrum nigrum, with its bright green pleated leaves and stately flower spikes.

Pittosporum 'Tom Thumb', a dark version of the florists' favourite foliage plant, has almost black leaves which are so shiny you expect to see your face in them. Ligularia dentata 'Desdemona' has sculptural leaves with black stems and dark mahogany undersides. Here the ruthlessness of the serious gardener comes into its own: this plant's bright orange flowers must be removed before they spoil the effect.

Many of the plants are evergreen, so the black and white effect in Mrs Bunn's border will continue through the winter, when snowdrops will appear between the black leaves of the ophiopogon, and dark hellebores will come into flower.

Black-flowered bulbs were easy to find. Tulip 'Queen of the Night' is very dark, as is Fritillaria camschateensis, like an elegant version of a crown imperial. Hermodactylus tuberosus, the widow iris, has scented translucent green and black flowers. The annuals sweet pea 'Midnight' and nemophila 'Pennie Black' produced plenty of flowers in the summer, along with black pansies and violas.

Next year she may try seeds of Rudbeckia occidentalis 'Green Wizard', a peculiar perennial introduced this season by Thompson and Morgan. This plant, with flowers of black central cones surrounded by green sepals, was the pet of T&M's chairman Keith Sangster, who came in for plenty of teasing from his colleagues. They were convinced this oddity would never be popular but so far this year, to everyone's surprise, it is among the company's top 10 best sellers.

Mrs Bunn has ordered 'Souvenir du Dr Jamain', an old hybrid perpetual rose with dark maroon flowers. Another possibility was Rosa pimpinellifolia 'Grandiflora' which has single white flowers and black hips. She has had great fun searching for plants, and is particularly pleased at the way the colours have kept going into the autumn.

Ian and Annette McMullen, who are extending a garden in Kent, chose a black theme for one of their new beds. Returning from Sissinghurst, they agreed that the idea of a white garden like Vita Sackville-West's had become old hat and decided to have a black border. 'It started as a joke,' said Mrs McMullen, 'but it is beginning to work.'

They began with the dark-leaved shrub Cotinus coggygria 'Royal Purple', and have tried to restrict themselves to plants which are either really black or have a black connection. So penstemon 'Raven' and tulip 'Black Swan' have been allowed, although neither is true black. The border gets plenty of sun, which is important if the dark colours are to stand out.

Several of the black-flowered plants are slightly odd, but none more so than a plant shown earlier this month at the Royal Horticultural Society show in London. Ralph Northcott, of Westfield Cacti, was showing a big pot of Caralluma mammilaris - a succulent with shiny black flowers. 'It has created quite a sensation,' he said, beaming. 'I would say there has been more interest than in any other plant I have ever shown.'

This was not so much due to its flowers as their scent, which was like something appalling one had trodden in on a city pavement. The odour attracts flies which pollinate the flowers. 'If the sun were on it,' Mr Northcott said, 'you would be able to smell it right across the hall.' In spite of the scent, or perhaps because of it, Mr Northcott sold several plants, proving that however odd a plant is, there is a gardener somewhere who wants to grow it.

Avon Bulbs, Burnt House Farm, Mid-Lambrook, South Petherton, Somerset TA13 5HE has a large selection of bulbs including unusual fritillarias and alliums. Mail-order catalogue: send four second-class stamps. Hazeldene Nursery, Dean Street, East Farleigh, Maidstone, Kent ME15 OPS has a wide selection of pansies and violas, including several blacks. Send sae for catalogue. Thompson & Morgan, Poplar Lane, Ipswich IP8 3BU. Seed catalogue offers many dark varieties.

Anna Pavord is on holiday.