In the wardrobe a couple of seasons ago, brown became "the new black"; has a similar fashion trend swept the horticultural world?
Both the style and the content of our gardens have always been subject to changing influences. Plant-hunters and the designers of the great estates, made their mark. Gardeners acquired plants from the New World; rushed to buy tulips in the 17th century; plundered elements of the cottage garden. And, in the Eighties of this century there was a surge of enthusiasm for conifers and heathers, promoted by Bloom's nursery to complement the circular beds they advocated.
Creating a new plant variety is, of course, a far more time-consuming process than changing a skirt length. Perfecting new breeds doesn't happen overnight, and building up enough stock to make them commercially viable can take up to 10 years. So the garden centres have to think several years ahead to make sure their growers will be able to satisfy the predicted demand.
Plant buyers in all the big chains stress the constant need to find something different and distinctive. If a new plant is to prove popular, it has to have an improved scent, or be more resistant to disease; smaller varieties also sell well, as we garden in smaller and smaller spaces. Many new breeds are put up for inspection at the big trade shows, but often the buying doesn't take place until later. Buyers take photographs and make notes, but unless they believe they have a sure-fire winner they are likely to sound out opinion among colleagues first, and make the buying decisions later.
The larger chains - such as B&Q - which has 260 outlets across the country, can have a huge influence on supply. Most of their regular growers have many plants in their trial grounds, which may never be offered to the garden centres. But if a buyer asks for something, and it already happens to be on trial, its progress can suddenly be advanced.
However, it is the smaller nurseries that tend to do more to encourage research, sometimes by getting together in groups to try to influence growers. Frosts Nurseries buy the hardy stock for their three branches from 80 suppliers in different parts of Britain and continental Europe. These suppliers grow almost exclusively for them, and so Frosts themselves are able to dictate what is grown. They can also encourage the development of new lines they feel would be popular. David Brakefield, in charge of buying hardy plants, is particularly keen to see a new variety of viburnum - winter-flowering, scented, and evergreen. His horticultural training tells him it is feasible; buying trends show that it would sell well; now he has to try to persuade his growers to invest money in the research.
Fashion is probably best described as what the consumer wants - a delicate balance between what is seen to be available, either in nurseries or through magazines and television, and the requirements of a changing lifestyle, with smaller gardens and less time to spend in them. But we are also more aware that the attractiveness of our surroundings can be enhanced; a balcony or a passageway doesn't need to be bare. So the trend is towards plants with immediate impact. Building a garden over several years is a dying art.
Buyers are divided on how they assess what influences our tastes. Ian Howell of B & Q is under no misapprehensions about the influence of television. When a little-known plant, liriope, was featured in a TV garden design programme several years ago, demand tripled overnight, but, as it is difficult to grow, it was three years before demand was met.
Ian Howell believes it is the big gardening shows, such as Chelsea, that most influence the colours we choose. Jan Habets, of Plant Publicity Holland, who promotes Dutch nursery products across Europe, thinks that the many magazines on sale are far more important - and not necessarily just the gardening ones. He believes many of us regard a garden as little more than another room to furnish, and, given the chance, we want to continue the colour of the carpet out into the tubs on the terrace. Marks & Spencer, whose influence on horticultural trends is limited but significant, is currently taking colour co-ordination a stage further. Confident that we shall all be wearing lilac next spring, M&S has been selling a series of bulb kits to match.
Back in the more mainstream garden centres, they tend to dismiss the idea that we buy plants according to any colour scheme. They say our buying habits show that we want colour, not co-ordination. In the past few years we have favoured pastels, but this last summer we have been looking for hot colours; maybe this was an attempt to compensate for the lack of heat from the sun.
Of course, there are ways of starting your own fashion. If a plant catches your eye, or if you remember a specimen from the past and want to get hold of it, the Royal Horticultural Society's annual publication, The Plant Finder, gives tens of thousands of plant varieties and advice about where to find them. You can then split them up, or take cuttings to give to your friends, and start a trend, albeit a localised one.
Or you may want to get ahead of the trend. Insider tips for next summer include a hydrangea called "Hanabe" - "firework" - with double flowers in white with a touch of pink, against a very dark leaf. And look out, too, for a new variety of Petunia surfinia, called `Limelight'. The leaves have creamy variegations, and the flowers are bright pink. Like it or loathe it, the people who can influence our taste have picked it out for us. You have been warned.
`The Plant Finder 1998/99' published by Dorling Kindersley, at pounds 12.99, is available from most garden centres and big book shops, or direct from the RHS on 01483 211113