VAL BOURNE says if you've lost the plot, you need to look at the borders

You will be familiar with the term FAQ if you are a web browser. It stands for frequently asked questions' and one of mine, being a gardener and garden writer, is "Can you come and see my garden?" Once there I'm asked for help usually because the garden owner senses their plot could be better. Often the problem is down to a lack of understanding about what makes a good border. It isn't necessarily flower. In fact, gardens rely more on good foliage than fleeting flower.

The first basic lesson is that foliage comes in different colour ways and these include sun-loving silvers, shade-loving golds, accommodating greens that tend to grow anywhere, warm reds and cool or warm variegated foliage. Sun-loving silvers need good drainage and full sun to keep their light glimmer and stiff stems. They also thrive on poorer soil because most have deep-root systems. So don't feed them: it just makes them floppy and soft. If you're gardening on heavy clay, or in a persistently high-rainfall area silver leaves will take on a dull, sage-green patina that's very unattractive. They will probably struggle through your winters too, so opt for greens and golds instead.

Most silver plants flower in summer and colour tends to be pastel and includes blues, pinks, lavenders, purples and pale-yellows and occasionally deep-pink or red. You can create a swathe of soft colour and you could add deep-blue agapanthus, dusky purple and pink origanums, or dark sedums like Purple Emperor' as a contrast.

On the foliage front there are woolly-leaved salvias and phlomis, scalloped ballotas, spiky lavenders, needle-leaved dianthus, lacy artemisias and fine-cut anthemis and some excellent silvery nepetas. Mixing leafy shapes and textures is another essential in any border.

Dark-red leaves look well with silvers when used sparingly and you could add purple flowers to bring out the foliage. In the picture there's a flowering allium picking up the new, purplish leaves of Actaea simplex James Compton'. This fragrant white-flowered cimicifuga peaks in September or later. But the foliage is sensational from early May onwards. Dark foliage can also make an excellent foil for pale-apricot, peach-orange and pale-pink flowers - whether it's irises, oriental poppies or roses. These paler colours are easily lost in the garden setting. But they glow luminously placed among dark, dramatic foliage.

When it comes to gold-leaved plants most will scorch in bright sunshine so you should never put golden plants in full sun. Let them light up dark, shady corners instead. Similarly, leaves splashed in golden variegation can also add light and contrast to deep shade. But always surround variegated leaf with lots of good greens. Yellow, orange and blue flowers mix best with golden foliage. But cool pinks are truly vile next to golden leaves.

Luckily, most green leaves are accommodating and come in a range of shapes and tone varying from cool grey-green to warm rich-green. Grey-green foliage is best in good light: it looks dull and almost insipid in shade. Dark-green foliage is a lively addition and it can be made more vibrant with a touch of red. My fern borders are overhung with red berries (from Viburnum opulus Compactum') and the fronds mingle with the herbaceous (not shrubby) Potentilla Gibson's Scarlet' at ground level. Rich, high-gloss greens are also good with clean-white, bright-yellow or true-blue flowers as well.

So go out now and have a look at your leaves and see if anything needs moving. Because it will show much more now than it will next spring.