Gardening: Planting by numbers

Behind every successful garden there's a plan of action. In the first of three extracts from his book 'Garden Magic', Nigel Colborn perfects the urban plot; PART ONE

AS THE politicians slink back to Westminster and the academic year gets underway, cold nights and shortening days give our gardens even more allure than they had in midsummer. Foliage is buffed up to gold and russet - warm, gentle colours to contrast with the brightness of the autumn flowers - but there is so much more to this season than the present display. This is a time for absolution, when past errors are dissolved in the natural decay of the plants and flowers around us and we are given another chance. The perfect moment to renew ideas, to reshape planting, overhaul your garden's design and perhaps, if you want to be daring, to try out something different, even revolutionary.

Whatever your level of gardening, design has never been so important. In recent times, the "style" industry has diverted its attention from trendy kitchens and pretentious bathrooms and seems hell-bent on creating al-fresco "chic" in every backyard. Not that one should disparage. One good thing that influential trendies are doing is to displace stuffy establishment designers - so obsessed with clipped yew and oh-so-genteelly colour-coordinated borders - and to encourage originality. The avant garde is at least experimenting with new textures, new shapes, new lines and frequently comes up with a total reappraisal of the gardening concept.

Ultimate success, though, however brilliant the design, depends on the planting: that is, on the plants selected and, more importantly, on how well they are arranged. Every garden needs architecture so that the allotted space is put to optimum aesthetic and practical use, but good planting will always be a prerequisite for that special pleasure which is generated by a constantly changing pattern, month by month, season by season.

Ground rules for good planting are pretty straightforward. First, it makes sense only to grow species suited to the conditions that prevail in your garden. If you live on chalk, don't bother with rhododendrons; if your garden is frosty, learn to live without subtropical palms. Secondly, grow only the plants that you enjoy. If haughty-cultural friends scorn your beloved dahlias, or your French marigolds, let them. And however trendy euphorbias may be, leave them out if you hate them.

Finally - and this is the trickiest one - the plants must be combined to achieve the most pleasing associations, not only of colour, but of shape, texture, outline and character. Don't worry about getting it right first time - no one does. Even Gertrude Jekyll, originator of 20th-century planting styles, fine-tuned her borders for 40 years, and derived enormous pleasure from the constantly changing picture. Creative planting is a plastic art form, even in the most rigid of designs; once hooked you will want to go on trying different combinations. Furthermore, you will often find that the most ravishing mixtures happen quite by accident.

On the practical front, this is the time of year to give your garden a horticultural MOT. Is your soil in good heart? If the tilth isn't crumbly, and if there are compacted patches that do not drain properly, now is the time to put things right by digging in organic matter. Home-made garden compost is useful for opening up soil structure, or spent mushroom com- post or leafmould. If you have a problem with perennial weeds, consider digging out their roots now, but leave any fertiliser applications until next spring.

Autumn is the optimum season for planting, before the soil has cooled down to winter temperatures. As the leaves fall, and summer growth dies back, you are left with an almost clean canvas, making it easy to see how the three main elements of good planting can fall into place. First of these is to create a well-planned, boldly stated backbone or profile - especially important when the lushness of summer vegetation has withered away and left little to soften the outline of the man-made elements. Trees and shrubs, especially evergreens, are useful, making focal points in winter but becoming leafy backgrounds to the summer display. Their shapes can be as architectural as buildings, be they tall and columnar, rounded, conical or tiered.

Outline plants will preside over an understorey of lower-growing species,which may be less shapely, but provide the garden with much of its character. It is with this that you can have the most fun, arranging contrasting foliage types - fussy ferns with bold hostas, maybe - and where you can build up your colour schemes. By experimenting, you can develop different moods, from brassy, flower-strewn displays in bright sunlight to quiet, restful hues in shade.

The possibilities are limitless. Styles can be formal, with plants neatly spaced, or as naturalistic as a genuine wild landscape. You could meddle with scale, positioning extra-large plants, for example, smack in the front of a border, to jolt the senses, or even to create a visual joke (no one says laughter is forbidden in a creative garden). Colour changes can be engineered, running from bright yellow in spring, perhaps, through summer pinks and purples to blue, or back to gold for autumn. Plants with bright berries or interesting seed heads will be looking superb right now, especially if they have been congregated to make a bold display, perhaps positioned so that they catch early morning sunshine.

Whatever your preferences, this is the season to get cracking. But plan before you plant, and develop a general composition in your mind before selecting specific varieties. Over the next three weeks, starting with how to create a shady urban plot, we will be publishing a series of complete garden plans - including planting recipes, preparation and maintenance, and a plant ingredients list - from Garden Magic, each of which can be replicated precisely - literally planting by numbers. But this approach is also designed to initiate ideas, as well as dictating specific planting plans, and as such can be used as a springboard for your own, unique creative process. Happy gardening!