Jane Powers cherishes the challenge of choosing plants for perennial borders
One of the hardest things in gardening is designing a perennial border. You can bung a bunch of plants together and call them a border, but whether they make sense is another matter.
First, let's be clear about what a perennial is, in gardening terms. It is a non-woody plant with a serviceable lifespan of two or more years - that is, a soft-stemmed plant such as a delphinium or a hellebore. This means it's not a tree or shrub; nor is it an annual (which flowers, sets seed and dies in one year, as in marigold or nasturtium).
Some perennials are evergreen; others disappear underground for part of the year. Some are naturally long-lived, surviving for decades even if they receive little attention. Peonies and oriental poppies, for instance, return year after year in the most neglected of gardens. Other perennials have short but dramatic lives (lupins and some aquilegias, for example), giving it all up in their first couple of seasons. Such plants may persist wearily for longer periods, but they are best turfed on to the compost heap as soon as they lose vigour and stop paying their way. Forget about charity if you want a good-looking garden.
There are multiple challenges in choosing and combining plants successfully in a perennial border. First, there are the practicalities: finding plants that suit the growing conditions, avoiding gaps and ensuring a succession of blooms or other interest over the season. Then there is design: arranging plant shapes, colours and textures to make a pleasing picture. Lastly, there is the all-important factor of creating something richer than a mere assemblage of plants, something that arouses a feeling or evokes a place or memory. In other words, a planting scheme should speak to you, eliciting a response other than a prosaic: "Oooh, lovely flowers."
Plenty of perennial borders are exemplars of function and clever design, but they lack that final, emotional ingredient and so are mute concoctions. Then there are the overly crowded conglomerations of avid collectors, who can't see beyond the charms of individual plants, and have crammed as many disparate species as possible into a space. Which isn't to say that collectors can't have borders that speak, or even sing - in fact, two gardens with exceptionally euphonious plant combinations belong to the collectors Helen Dillon and Jimi Blake (see www.dillongarden.com and www.hunting brook.com).
Achieving different dynamics through different kinds of planting is explained nicely in Michael King's new book, The Perennial Garden. He gives the simple example of two rounded forms of differing heights and one upright form, in this case a low mound of Alchemilla mollis, a taller and more billowy mound of Campanula lactiflora and an upright spire of delphinium. Arranged as a group, as is often the traditional way, they are "balanced", but they also neutralise each other and so lack energy.
Instead, he suggests, imagine great islands of the tall, soft blue campanula, surrounded by seas of foamy alchemilla, with jets of delphinium erupting here and there. Of course, such expansive planting schemes are not feasible in the average domestic garden, but we can certainly borrow some of the thinking - and be bolder and less formulaic in our plant arrangements. And those with country gardens are blessed with large blank canvases where they can experiment with more exciting combinations.
Such perennial schemes, increasingly popular in the US and northern Europe, take their inspiration from native plant communities: from the prairies and deserts of North America and the steppes, meadows, moors and other naturalistic plant societies elsewhere. The fact that nature is echoed, or somehow referred to, strikes a chord with us, making the experience richer and more emotional.
It is the opposite of the traditional herbaceous border (an Edwardian contrivance, when labour costs were low), where vast amounts of manpower were expended in halting nature's progress. Clumps were divided, replanted and renewed every year or two, in order to maintain a largely unvarying creation.
In today's schemes, only species that suit the site, soil and climate are used - so less mollycoddling is required. And, more and
more, plants are chosen because they are compatible in vigour and growth habit, meaning that bullies don't have to be constantly dug up and divided.
This new kind of planting requires less intervention, but it still needs to be managed. Some plants, such as heleniums, may be selectively pruned in late spring or early summer, to delay flowering, increase the number of blooms and reduce height. And although plant skeletons and seed heads are important parts of the winter garden, they must be whipped away as soon as they turn to mush.
In this kind of planting, seasonal transformations - and long-term ones, too - are celebrated rather than avoided. The gardener is more aware of and more engaged with growth and change. As Michael King so succinctly puts it: "Gardening is a process, sometimes with a beginning, but never with an end."
The Perennial Garden, by Michael King, is published by Mitchell Beazley, £25