Gardening: Get cracking for the cottagey look: Pristine paving is out. Michael Leapman searches for low-growing greenery to spread among the stones

TASTES change. When we first moved into our London terrace house nearly 30 years ago, there was a small area of crazy paving just behind it. The fashion then was for neatness and order: so to free it from any threat of unruly vegetation, I would soak it every year with a comprehensive path weed killer.

Last year we had the garden redesigned but kept the paving. In the summer we use it when we can for eating and drinking. Today's fashion, though, is for gardens with an informal, cottagey feel: hard edges softened by vegetation. Instead of having naked paving stones, we decided to cultivate low-growing plants between them, letting the greenery spread along the cracks.

Finding the right varieties proved less straightforward than it sounds. None of our nearby garden centres offered selections of plants specifically for this purpose, nor could we find a book that addressed the question. 'Low-growing alpines' was the best general advice we could obtain; a paved environment suits them because they require good drainage. So we ferreted round the labels in the alpine sections, looking for those that promised restricted height and tightly knit foliage.

The most common are the small Sedums, and we bought a few of those. Among others we tried were Androsace (rock jasmine), Raoulia australis (silver moss) and Frankenia thymifolia. Most are supposed to form mats or hummocks of foliage. A few did, but some declined to grow any bigger, and others were overwhelmed by weeds or the clump-clump of heavy feet.

The most successful group were the numerous small varieties of thyme. Most of these spread vigorously almost from the moment they were planted. One plant we had retained from the old garden was Helxine soleirolii (mind-your-own-business). This is such a vigorous grower that gardening books often class it as a weed. None the less it has many of the properties we were looking for: although it has no flower to speak of, its neat foliage follows the cracks in paving and seems to enjoy climbing the brickwork at the side. Another long-established resident was moss, which gives stone a pleasingly rustic appearance. We also tried bringing home some different species from country walks, but they seldom took root successfully: moss seems to be very specific to its place of origin. By the end of last summer more gaps between the paving stones remained unfilled than filled.

At this year's Chelsea Flower Show we sought suggestions from the Royal Horticultural Society's advice centre. Two of their recommendations were Sagina aurea, which forms evergreen mats, and Acaena microphylla (New Zealand burr), with its striking bronze foliage and red burrs.

Then in the mass of promotional literature sent to me before the Hampton Court Flower Show last month, came a note from Siskin Plants of Chartfield, Suffolk, that seemed to address our need. The nursery specialises in alpines and dwarf shrubs and was introducing at the show a collection of six low-growing alpines, chosen specifically for spreading along cracks in paving.

I was abroad during the show but when I returned I phoned Chris Wheeler, a partner in Siskin Plants, to ask him what the response had been. From his experience it is clear that many other gardeners share my problem.

'The collections went very quickly,' he said. 'We had enough plants to make up about 100 of them. We had about 15 varieties for paved areas and we asked people whether they wanted them for shade or sun and then picked out the six that were best for them.

'We also had some plants suitable for putting in clumps. A lot of people nowadays are leaving three- or four- inch gaps or pockets for plants in their patios and paved areas, to soften the effect of the stone. You can grow a wide range of alpines in those conditions.'

Ideally, plants for cracks should be capable of running beneath the paving and then surfacing where they detect daylight; many of the small lobelias have that quality. Flowers are of secondary importance. Although many miniature alpines look stunning when in flower, it is for a comparatively short period. We were looking for something primarily with neat, vigorous and long-lasting foliage.

Mr Wheeler warned me of the pitfalls: 'First you have to make sure they don't look too much like the weeds you're trying to suppress. And they mustn't mind being trodden on. There aren't many that will take constant treading, though.' And of course it all takes time. Traditional cottage gardens have been there for years. Natural selection has had plenty of time to operate; plants that have thrived have overwhelmed weaker ones. We are still working on it.

Siskin Plants, Davey Lane, Charsfield, Woodbridge, Suffolk IP13 7QG, tel 0473-37567.

FOR CRACKS BETWEEN PAVING

FOR SUNNY AREAS

Antennaria parvifolia Height 6in. Silver leaves, white button-like flowers

Cymbalaria muralis albiflora (toadflax) Height 2in. Tufts of ivy-shaped leaves, white flowers

Jovibarba sobolifera Height 2in. Rosettes of yellow-green leaves, yellow flowers

Oxalis magellanica Height 1in. Bronze leaves, white flowers

Potentilla eriocarpa Height 2in. Grey-green leaves, yellow flowers

Sempervivum (houseleek) Height 2-8in. Many kinds; rosette leaves

Thymus serpyllum Height 1-2in. Many species; various colours

Veronica prostrata 'Nana' (speedwell) Height 3in. Deep blue saucer-shaped flowers

FOR SHADE

Epilobium crassum (willow-herb) Height 2in. Fleshy red-tinged leaves, pink flowers

Hypsela reniformis Height 1in. Shiny leaves, crimson flowers

Leptinella potentillina Height 1in. Divided green and bronze leaves, yellow flowers

Lobelia Height 1in. Several small varieties, white or blue flowers

Mazus reptans Height 1in. Toothed leaves, white/yellow/ mauve flowers

Mentha requienii (Corsican mint) Height 1in. Carpet of tiny, mint-scented leaves

FOR POCKETS IN

PAVING

FOR SUNNY AREAS

Achillea Height 3-5in. Several varieties; various flower colours

Arenaria purpurascens Height 1in. Mauve, star-shaped flowers

Armeria juniperifolia Height 1in. Small leaves, pink/white flowers

Aubretia Aubrieta deltoidea 'Variegata' Height 4in. Variegated foliage, purple flowers

Cephalaria alpina Height 4-6in. Lavender blue flowers attract butterflies

Dianthus Height 3-6in. Many small varieties

Erinus alpinus (fairy foxglove) Height 2in. Cushions of foliage with pink/lavender flowers

Frankenia thymifolia Height 2in. Red-tinted foliage, pink flowers

Helianthemum (rock rose) Height 4-8in. Evergreen, many varieties

Hypericum trichocaulon Height 1in. Trailing, crimson buds open into yellow flowers

Origanum microphyllum Height 4- 5in. Aromatic leaves, pink flowers June-Sept.

Sedum Height 2-6in. Many kinds

Sempervivella alba Height 2in. Red-tinted leaves; white flowers

FOR SHADE

Arabis ferdinandi-coburgii Height 4in. Pretty foliage, white flowers in spring

Campanula (bellflower) Height 3- 5in. Many varieties; blue/violet flowers

Festuca glauca minima Height 3in. Blue tufted grass

Parahebe bidwillii 'Kea' Height 2in. Glossy leaves, white crimson-veined flowers.