Magicians who can make urban gloom disappear

For years I have driven past it, marvelling at its strangeness: a ruined Victorian vicarage towering over one of the most godforsaken crossroads in Hackney, east London. Buddleia sprouted from its crest, pigeons flew in and out of its empty eye sockets. No matter how fine the weather, or how bright the sun, it always seemed shrouded in Gothic gloom.

One day, every window was bursting with life and colour. Owls and bats flitted through a blue heaven visible in the upper slits, angels floated on clouds in the middle windows, a black gospel choir sang below. A modest notice indicated that Freeform Artworks, authors of this magical architectural transformation, might be found in the dilapidated Georgian house next door. They turned out to be a jovial bunch, pioneers of the "bi-art" game which has become so ubiquitous that we take it for granted.

British developers now routinely disguise building sites with trompe- l'oeil edifices. In France, this has led to the wrapping of the Arc de Triomphe in a gigantic tricolour to celebrate the 200th anniversary of the revolution of 1789, or the sheathing of the obelisk on the Place de la Concorde in a 70ft pink condom to reinforce the message about Aids.

The fine art inspiration for this kind of public art comes from Christo (who giftwraps the Reichstag in Berlin in the middle of next month) and Claes Oldenburg (maker of 50ft-high clothes pegs). Freeform occupies altogether quieter ground, casting its spell on blighted areas of the inner city, often on a very small scale.

Four years ago, the group won a British Gas "Working for Cities" Award for its exotic beautification of the harbourside at North Shields and for its design of the town's dazzling Fish Quay Festival. This took place again last weekend and the group's design has been shortlisted for one of this year's British Gas Awards.

In London, Freeform has designed some of the most dramatic developers' hoardings, yet, on its home territory in Hackney, the charitable trust has been working on a scale aimed to delight the youngest child. The Stonebridge Common, E8, of my London A-Z is Snake Park to local children, who play on the back of a brightly coloured mosaic serpent coiled across the grass of a tiny public garden.

Down an alley behind nearby Hackney Town Hall, railings rock like an Op Art illusion, the path stopping at a gate proclaiming Hackney Grove Gardens. This was a burnt-out toy factory before Freeform got to work. Now it is full of exotic shrubs and surreal artistic touches, such as curiously carved pillars and chimney fragments and bits of window frame set into a boundary wall, ganging together to suggest a ghostly dwelling. Children from a school for the mentally handicapped did these. Now funds are needed to maintain this odd house and garden before it becomes completely overgrown.

A few streets away, we enter, courtesy of Freeform, the Orient: a Vietnamese pagoda, a Laotian stupa (a domed shrine) and a model of a Cambodian temple, all set in an exquisite miniature landscape bounded by blue plaster hills. This is Freeform's much-liked contribution to a local centre for refugees from the Viet peninsula.

In nearby London Fields, two Dali-esque flower-sellers made from mosaic and shells can be seen presiding over a flock of pebble sheep. This was where, historically, sheep grazed for the last time before being herded down to the slaughterhouses of Smithfield Market.

Elsewhere in surrounding streets, Freeform has worked with residents to create a ceramic mural, to bring painted clouds to the walls of an otherwise ugly car park and vivid colour to the underside of bridges off the beaten track.

The artists involved are a mixed bunch, each brought in on a contract by Freeform as the work requires or the project allows. "One of our aims," says Alan Rossiter, art director of Freeform, "is to create work for artists; Hackney has a higher concentration of artists than anywhere else in Europe."

"But," adds Martin Goodrich, co-director of Freeform, "we are working with artists to help local people redesign their own environments."

The group is visited by students of landscape design from throughout Britain. Increasingly, its work is copied, notably in giant advertising hoardings but often using slick techniques that Mr Goodrich views with some contempt. "Call us Luddites if you like," he says, "but computer- controlled, jet-spray painting has no individuality - we see the life taken out of our work. We like the evident human touch, together with a bit of wit."

Having just lost his grant from the London Borough of Hackney, Mr Goodrich is understandably sore at the red tape he must cut through to put Freeform's ideas into action. "We're concerned to establish notions of good professional practice among artists working in the landscape field where art touches architecture in a nitty-gritty but delightful way. This way, artists stand a better chance of getting their work taken as seriously as that of architects and engineers. They deserve to be seen, should be seen and should be paid as equal partners."

Who is going to disagree? In the Eighties, we planned for permanence in the guise of great urban "masterplans" and megastructures such as London's Broadgate and Canary Wharf. We planned for permanence and dreamt of perfection. Now, a little sadder and wiser, we know better. The best we can do for the poorest parts of our cities right now is to make do and mend. And beautify. And give everyone a chance for some delight and fun.