Kew here: preparing a garden for the public

Alan and Ann Sandall made an exceptionally generous bid for me in The Independent charity auction, wanting advice on repairing the damage done to their Kew garden by last winter's savage weather. With various neighbours in the same road, they open every year for the National Gardens Scheme and they needed to get the place back into shape for their opening this May Bank Holiday weekend.

Ann Sandall had other concerns, too: shade from neighbouring trees, a hungry dry soil and a tall, ugly fence formerly screened by summer jasmine and white solanum. Both had been badly beaten up in the freeze. She wanted ideas for an unsatisfactory area at the bottom of the plot and general advice on replanting the borders either side.

Most town gardens are longer than they are wide and the Sandalls' plot, though only 15ft from fence to fence, runs 120ft from the back of the house to a railway embankment at the bottom. A door from the kitchen leads directly on to a south-east facing terrace, extended four years ago, with a path running down the right-hand side. Below the border on this boundary are big clumps of bamboo, and a composting area (Alan Sandall's speciality). At the bottom on the right is the area which most needed re-arranging.

On the left, the star of a wider, undulating border is a big Magnolia x soulangeana 'Rustica Rubra', a really superb tree, but compromised, I thought, by a Chusan palm (Trachycarpus fortunei) growing too close in front of it. The Sandalls already had a monster Chusan in the right-hand border. To get the best view of the magnolia – a tree of great presence even when it is not in bloom – this smaller Chusan needed to go.

In order to give the garden extra variety and interest, I suggested that the Sandalls might think of their plot as providing four different "happenings", each with its own distinct character. In this respect, the length of the garden is a great advantage. The top half close to the house can be much busier than the bottom – a natural progression from razzmatazz to calmer, greener planting.

The orientation of the garden also means that the boundary on the left side is sunnier than the one on the right. That gives the Sandalls an excellent opportunity to vary the mood either side, reinforcing the differences by their choice of plants.

The boundary fences seemed slightly under-used and there were two reasons for doing more with them. It would give Ann an opportunity to plant more plants (as a self-confessed plantaholic, this must be a good thing) but those fences, fully clothed, would also provide more sympathetic backdrops for the borders.

Being wooden, they can't be loaded with anything too heavy. Nor should the Sandalls plant anything self-clinging, which might prise the boards apart as their wisteria is already doing. Climbers need something to hang on to and for light-limbed things such as clematis, chicken wire is ideal. You can scarcely see it and it is easy to fix in large panels flat against the fence. In other cases, wall shrubs could be splayed out and trained on sets of parallel wires.

On the sunny side, I suggested adding Trachelospermum jasminoides, a lovely, scented twining climber that flowers in August and September, often rather a dead time in the garden. It has glossy, evergreen leaves and is a paragon. It doesn't like competition, but is a steady grower that doesn't need regular pruning. I'd also chuck in at least four clematis, to flower from spring to autumn. The Sandalls could start with Clematis macropetala, move on to 'Ascotiensis', 'Perle d'Azur' or 'Etoile Rose' for summer, then finish the season with Clematis viticella types such as 'Abundance' or 'Purpurea Plena'.

Ann said she'd not been very successful with clematis and I wondered whether cats may be the problem. When they plant, they could try slipping a length of pipe over the stems and wiggling the pipe about so it stands in the ground on its own feet. The pipe keeps cats away and stops mice nibbling the shoots, which they often do. Mulching would help, too. Clematis like their heads in the sun but roots that are cool; a mulch, as well as providing food, helps retain that coolness. In dry town gardens, all new plantings need watering all through summer. Roots won't be well established before next autumn.

To achieve the changes in mood we'd been talking about, we agreed that stuff planted in one border should not appear in another. Peonies – Ann's great weakness – could go anywhere and provide the leitmotif that knitted the whole garden together. In putting together satisfying groups of plants it also helps if you think of foliage first and flowers second. If leaves are well contrasted, then the border will feel good, even if the flowers are not out. The flowers become the icing on the cake, not the raison d'être.

Ann had a white theme going in the shadier right-hand border and I thought she might build on that by adding plants such as Anemone blanda for spring, Astilbe 'Irrlicht', Cosmos bipinnatus 'Sonata White', Dahlia 'Hamari Bride', Delphinium 'Sandpiper', white foxgloves, white Echinacea, Gillenia trifoliata, white honesty (Lunaria annua), white narcissus, Pulmonaria officinalis 'Sissinghurst White', and on the fence behind, Rosa 'Iceberg' or the lovely white Clematis 'Marie Boisselot'.

Beyond that border is the "problem" area for which I suggested three treatments. All would mean emptying the area of everything except a clump of bamboo, which the Sandalls wanted to keep (though it will be troublesome) and a gingko. It's a shady, hemmed-in patch but box would survive, planted in a simple geometric pattern. That was the notion the Sandalls liked best. They'd have to dig over the area and incorporate masses of good compost and bonemeal. The ground will be hungry with the gingko and bamboo already feeding off it and the box hedge needs the best possible start. When it is planted, they can mulch the whole area with gravel and perhaps stand a few big pots on the gravel in the box compartments.

But you can improve a garden by taking things out just as much as by putting things in, which is why I suggested some editing in the bottom left-hand area of the garden. Out with the roses (there are plenty in other places). Out with the lavenders (ditto). Instead, I suggested the Sandalls might think of this as a foliage border, majoring in ferns. Ferns are easy, fantastically handsome and need little attention, apart from cutting the dead fronds away in March.

As a centrepiece they might think of introducing a tree fern (Dicksonia antarctica). They are not expensive if you buy a British-raised seedling. They could also include Adiantum aleuticum, A. pedatum, A. venustum (maidenhair), the hartstongue (Asplenium scolopendrium), Cyrtomium fortunei (evergreen), most Dryopteris (male fern), Polypodium interjectum (evergreen), P. vulgare (evergreen) and all other polypodies, various kinds of Polystichum. All these will grow well in relatively dry conditions.

There was some housekeeping to do: stripping off the lower leaves of the black bamboo to reveal the stems; pruning the choisya to take out some of the yellowing growths (best done after flowering); cutting back some of the gaunt stems of the Euphorbia mellifera to force it to sprout from the base; cutting back the Melianthus major; getting rid of the old foliage of the Helleborus orientalis, badly affected by black spot. Are the Sandalls now where they want to be? I hope so.

The garden at 38 Leybourne Park, Kew, London TW9 3HA is open (with Fiveways and No 31) tomorrow and Monday (2-5pm). Combined admission £5