Peas and beans add height and colour in the garden, as long as they get the right support when they start climbing, writes JANE POWERS.
IS THIS A twiner? A grasper? A leaner? Or maybe it’s a scrambler or a clinger? These are the questions that should be asked of every climbing plant before we give it a home in the garden. The way that a plant with lofty intentions travels upwards is just as important as all its other attributes: leaves, flowers, size, vigour, and the kind of soil and conditions it likes.
The first time I grew sweet pea, I constructed a wigwam from shiny new bamboos and carefully planted some sweet pea at its feet. And then I waited for the tendrils to hoist the stems up, up and away in my beautiful bamboos.
However, the poles were so glossy that they offered no toehold at all for the little questing threads snaking out from the base of each leaf. Instead, some of the plantlets tied themselves together with their slender laces, while others grabbed onto other bits of vegetation and went off on journeys of their own design. What they needed was something to latch onto that was a suitable texture and proportion for their flimsy filaments. And, yes, I realise that this may seem like an inordinate amount of tendril talk, but sometimes it’s necessary to look at plants at a macro level in order to understand them. Sweet pea cannot easily clamber up a smooth surface – no more than we could shimmy up a greased pole. All they need is a little help in getting started: a twiggy morsel of birch for each plant, or a web of hairy string wrapped around the canes, or a bit of netting.
Sweet pea is the quintessential summer climber. Its impact is all the more potent because its sugary perfume – like all scent – bypasses the rational part of the brain, and heads straight for the limbic system, which generates emotions and memories. It has been with us as a garden plant for more than 300 years, when – the story goes – one of its first admirers, a Sicilian monk named Cupani, sent seeds to England and Holland.
The runner bean, although scentless, has a history that is even more venerable than that of the sweet pea. It has been grown as a food crop in south America for 2,000 years, and was probably brought to Europe in 1493 by Christopher Columbus. It was first introduced as an ornamental plant, because of its jewel-like vermilion flowers and its ability to quickly clothe an arbour with shade-giving leaves. Philip Miller in the 1754 edition of his Gardeners Dictionaryextols its virtues as an urban plant: "It will thrive very well in the City, the smoke of the Sea-coal being less injurious to this Plant than most others". He's right, it is an excellent plant for adding height to a small, town garden, provided that you give it plenty of water, and watch out for slugs and snails while it is finding its feet.
Scarlet runners (and pink and white ones, too) are among the easiest of climbers, ascending almost any kind of framework with their twining stems. Bean plants carry a huge amount of weight by the time they have ascended a couple or more metres – so they need a robust substructure. When putting up a wigwam or other frame, think of the weight of the foliage, add the weight of moisture from a bout of rain – and then add wind. I learned about this the hard way some years ago, when I found my proudly-grown and fully-fledged bean arch prostrate on the ground after a wet and breezy night.
With any climber – especially fast-growing annuals such as beans – remember that the shy infant plant with only a few frail leaves may turn into a great rugby-playing brute within a season. Other twining annuals, with less muscular growth, are the morning glories ( Ipomoea sp.) with their exotic trumpet-shaped flowers. A lesser known member of the genus is I. lobata; its elongated flowers look like a cross between Christmas lights and chilli peppers. The youngest blooms, at the top of raceme, are red, and as they age they lose pigment, fading to yellow and cream. There may be eight or 10 flowers per spike, all in different stages of their colour metamorphosis, so that a plant conveys a bunting-like effect, which gives rise to the common name: Spanish flag.
The well-named purple bell vine ( Rhodochiton atrosanguineum) is another festive climber. It hangs onto its support by looping its leaf stalks around it, in the same way that the pub goer who has drunk a little too deeply might link his (or her) elbow with the bus stop at the end of the night. It requires a fine support such as string or wire, and, because it is best seen from below, it is often grown suspended across the ceilings of conservatories or greenhouses.
Also using the leaf stalks as clinging devices is the Tropaeolumclan. Nasturtium is the best known of these, travelling epic journeys of many metres during the summer – until frost reduces its round leaves and flame-coloured flowers to mush. Its relative, the canary creeper, T. peregrinumis much daintier, with tiny, yellow, red-splashed blooms.
Both of these clamberers have minds of their own, but can usually be persuaded to attach themselves to a framework of chicken wire, if you want to hide an eyesore temporarily.
We'll talk about perennials another time, but a final climber, usually grown as an annual – but which is perennial in mild, sheltered gardens – is the Chilean glory vine ( Eccremocarpus scaber). It is a fine plant for adding colour to shrubs that flower in winter and sit there cheerlessly the rest of the year. It has tendrils, but it is also a leaner and a shover, hauling itself up through the inner branches to explode in a surprise eruption of ferny foliage and orange tubular flowers.