Urban gardener, Cleve West: Chuck out the yucca

Urban gardening can be frustrating around this time of year when gardening magazines up the ante for late summer colour. Drifts of heleniums, echinacea and asters to extend the season are just fine but many of us simply don't have the room. Containers are often the answer and even a wide shallow pot of montbretia is enough to lift the spirits. I had intended to beat the slugs by buying in a selection of dahlias to offset the feeling of summer deprivation, but things didn't go to plan and our garden this season has had to endure a certain amount of neglect ("What's new?" I can hear it growling in the background), because of holidays, an obscure viral infection (a parting gift from Nepal) and then several more weeks trying to catch up at the design studio, not to mention the allotment.

It's also had to put up with scaffolding, dust and Steve, our vociferous decorator-cum-rock band manager, as he grooves and croons while giving our house a much needed face-lift. The plants must have quivered when Steve first set foot in the garden as he invariably has more paint on him than a Hindu taking part in a Phagwah parade. He's earned the nickname "JP", being the living incarnation of a Jackson Pollock masterpiece, but fortunately for our plants and York-stone terrace he is meticulous in his preparation so everything is suitably protected.

One plant close to the fallout and justified for looking more than a little concerned is the aptly named Astelia nervosa 'Westland' that I'd planted in a pot a couple of years ago. This flax-like gem, like many plants from New Zealand, is a useful urban fixture that adds an exotic, architectural spin, but quite subtly, with purple-tinted silvery leaves and a distinct metallic sheen.

A nearby pot of Angelica 'Vicar's Mead', under-planted with the clover Trifolium repens 'William', had the intentional moody association. It sort of worked except that there wasn't enough sun for the clover to retain its deep purple tone and the leaves of the angelica were hinting autumnal hues quicker than expected - a sign of stress, proving that I was relying too much on the rain to keep it watered. A dahlia or two (of any colour) would have been more uplifting, but what with slugs, scaffolding and Steve's rendition of the Stones' "Paint it Black", they wouldn't have stood a chance.

Astelias have always been a useful standby ever since I was beguiled by A. chathamica with its steely hue and dusty bloom on arching leaves. It is the perfect alternative to yuccas which, unless blessed with a tall stem to keep the sharp needles out of harm's way, can be dangerous in confined spaces. Until then Beschorneria yuccoides had been the "safe" substitute, although its own safety can't be guaranteed in a cold winter and, like yuccas, the leaves aren't quite as arresting as those of astelia, particularly A. chathamica 'Silver Spear', which can reach a height of 2m in the right conditions. Of course, gauging a plant's attributes and its effect on a planting scheme must always be seen in the context of its neighbours, but astelias are extremely versatile. Urban gardens, seaside gardens, herbaceous borders, containers, mass planting ... I reckon this plant would even look good in a rockery.

You must judge for yourself whether you need subtle or screaming exotica. 'Silver Spear' is the all-singing, all-dancing attention-seeker. A. banksii is smaller, growing to around 1.3m, its leaves thinner than A. chathamica and becoming either more silver in sun or green in shade. As for our nervous (but now relieved) 'Westland', it will stay relatively small in its pot, but could reach around 1.5m in open ground.

I've already hinted that astelias will thrive on a certain amount of neglect; in fact they grow as epiphytes in New Zealand so need very little by way of maintenance. A reasonably fertile, well-drained soil suits them best in sun or shade and, once established, they are reasonably drought tolerant, even in a container. A sustained, severe frost could knock it back so you might want to give it some winter protection if it becomes the lynchpin to the structure of your garden.

I'm yet to see an astelia in flower in the UK, but these may be produced on female plants in late spring, the yellow-green blooms followed by orange berries in summer. Who knows, ours may have suffered enough trauma this summer to slip into survival mode and flower its heart out next spring.