Bamboo is one of those plants that people both desire and fear. They desire it, because it’s lush, jungly and instantly architectural in a way few other plants are, but it can also be invasive, so it’s unwise to head off to the garden centre without doing a bit of research beforehand. If you’re going to plant an invasive type, you need to surround it with root barriers.
So which bamboos are invasive and which not? There are two main types, depending on how their rhizomes grow: runners and clump-formers. Runners can be difficult to control as their long underground rhizomes will always try to colonise new areas. They include Sasa, Pleioblastus, Sasaella and Phyllostachys. Clump-forming bamboos tend not to be invasive and include Fargesia, Bambusa and Chusquea.
Although gardeners have worked out how to manage the spread of invasive bamboos, we are just beginning to understand the wide range available. A few years ago, the main trend among garden designers was for black bamboo. With this now established as a firm classic in the planting palette, designers are starting to expand their repertoire of plants. Lime culms (canes) such as Phyllostachys viridiglaucescens are particularly fashionable at the moment.
So why do garden designers love bamboos so much? Partly because they are evergreen, they create strong architectural structure all year round – hugely important in urban gardens. In a small space, they provide volume and drama, and they grow amazingly fast – new shoots can put on 10-15cm a day in the growing season. Yet they don’t block out the light, which means they make great screening plants.
If privacy is your principal concern, think about Phyllostachys nigra, which is very narrow but tall and so doesn’t take up too much space in small gardens. Besides ugly views there’s the issue of ugly noise, and the gentle sound of wind rustling through bamboo can block out both traffic and neighbours even more effectively than a water feature – with the bonus of being much lower maintenance than water. The other great advantage of bamboo is that it can provide strong foliage in a shady garden – Fargesia is particularly good where sunlight is limited.
Those are the basics, but designers will often create sophisticated effects, particularly with the shadows of bamboos – the light foliage creates great dappled effects in sunlight, or dramatic contrast under artificial lighting. In winter, the stems of bamboo can provide a feature in the same way as dogwoods. Try Phyllostachys aureosulcata f. aureocaulis, whose golden yellow stems blush pink in strong sunlight.
So how do you integrate bamboo into a planting scheme? First, look for a variety with plenty of good foliage. Try Phyllostachys bissetii, which is a fresh green even in midwinter, and surround it with flowers as punctuation points.
My favourite bamboo garden, la Bambouseraie in the south of France, can still teach us a thing or two about how to use bamboo in the landscape. Pleioblastus pygmaeus can be clipped to form a low-maintenance hedge, a bit like box, and Sasa forms a wonderful weed-suppressing groundcover. For inspiration closer to home, visit the Bamboo Garden at Kew, the Eden Project in Cornwall or the Bamboo Labyrinth at Alnwick in Northumberland.
CANE MADE PLAIN
Grow in your garden
Select the position for your bamboo carefully. Most bamboos prefer full sun but if you need a bamboo for a shady spot, a Fargesia is ideal.
Some bamboos, as you are probably already aware, are rampant spreaders and so it is important to contain their roots. Line the planting hole to a depth of just over half a metre with paving slabs or a specialist rhizome barrier (available from all good nurseries). Don’t make the mistake of using a pond liner as the roots will easily pierce it. Remember that bamboo roots can arch over low barriers, too, so make sure the top extends at least 3in (8cm) above ground level.
Try: Phyllostachys nigra, Fargesia denudata, Fargesia rufa, Phyllostachys aurea
Grow in pots
Another option when growing invasive bamboo is to grow it in a container of at least 18in (45cm) in diameter. Make sure the pot has good drainage, and keep your bamboo well watered at all times to ensure strong growth.
Try: Phyllostachys nigra, Sasa or Pleioblastus variegatus
FROM ALICE'S ARTICLE IN THE TIMES June 2008