Joe writes regularly for Gardeners World magazine and The Times 'Weekend' section.
His latest book'Joes Allotment is released in April 20009
The Plant Room
published by BBC Books in 2001
Joe Urban Garden Handbook was published by Quadrille
in August 2008
available from amazon- click here!
'Joes Allotment' for BBC
books to be published in April 2009
From The Times March 22, 2008
Small, enclosed spaces cry out for climbers. But architectural innovations now allow for a host of plants to go vertical.
Years ago, I had a dream that I was walking through a London where nature had completely taken over. Trees and plants had fought their way through the suburbs back into the city, and were growing absolutely everywhere: dangling from buildings, out of cracks in the pavement, covering walls. There was so much greenery I could hardly see a shopfront on the Holloway Road. OK, I know it was only a dream, but it was a good dream, good for my soul. Putting dreams aside, we all know that space in the city is seriously squeezed - any private outside space, be it a garden, back yard, roof terrace or balcony, is a bonus and should be enjoyed at every given opportunity. Unfortunately, the more limited the plot, the more it relies on hard paving materials to make it practical, and the plants are sacrificed and reduced to a bare minimum; the more the boundaries come into play, too, and are fundamental to its success. If they fail, it will be gloomy, claustrophobic and depressing; succeed, however, and it'll be well on its way to becoming an interesting and inviting space.
Traditionally, climbing plants - either self-clinging or grown on a support of wiring or trelliswork - are used in these situations to soften boundary walls and fences as well as the architecture of the building. Climbers also increase the general volume of vegetation without eating into the valuable ground space, and contrary to popular belief, a green backdrop will usually make a garden feel bigger, as it tricks the mind into not knowing precisely where the boundary is set. There are many climbers to choose from, but when you narrow it down to those that thrive in the inevitable shade cast by the tall buildings and trees of an urban environment, the choice becomes limited. For year-round cover in the form of evergreen climbers, the selection is further restricted to just a handful. The problem with most climbers is that they tend to get straggly and unruly, as they are designed, in the search for light, to scramble up anything they can get their little tendrils or aerial roots on. Ivy gets a bad press, but the variegated forms such as Hedera helix 'Glacier' and the Persian ivy Hedera colchica 'Dentata Variegata' are self-clinging and can help to lift dark areas by bouncing the limited light around. Clematis armandii has large, glossy, lobed leaves and scented white flowers in early spring, but does tend to lose its foliage lower down, and is hard to recondition. The sweetly scented star jasmine Trachelospermumjasminoides may be overused and seen in most show gardens these days, but for good reason, because it's as well behaved as climbers get, clothed to the ground in glossy green leaves. I have gone for the traditional approach and used climbers to green up the fences in my garden.
Recently, however, there have been some interesting developments where architecture and product design meet horticulture head-on. Although slow to gain traction in the UK, green roofs are now being designed into some new builds, as well as being retro-fitted on to older buildings that can take the weight. "Green walls", "living walls" and "vertical gardening" all mean pretty much the same thing, and are an exciting new breakthrough with a vast range of applications. Basically, they are a way of growing all sorts of plants, not only climbers, on to a vertical face, therefore maximising the planting where space is restricted and architecture is harsh. Although there are many architects who have embraced green walls in their design vocabulary (including Renzo Piano, the co-designer of the Pompidou Centre in Paris), it's an eccentric Frenchman, Patrick Blanc, who is the best-known pioneer in this field. He has transformed many buildings' façades into living art, planting beautiful, rich tapestries of lush foliage plants. There are various construction techniques used, from growing plants in glass wool within a wire metal frame, or directly on to a permanently damp felt to which their roots naturally cling, to planting them into louvred plastic modules with a built-in water reservoir. In all these cases, the plants are grown hydroponically, as necessary water and nutrients are fed through irrigation systems. As well as being a fabulous aesthetic solution, green walls also tick many environmental boxes, too. Plants significantly improve the surrounding air quality, reduce sound pollution, increase biodiversity, insulate buildings and, most importantly, cool our increasingly sweltering cities in the summer. The "urban heat island" effect means that our predominantly concrete, glass and tarmac cities hold on to heat and can be up to 6C hotter than the surrounding countryside. Sure, we'll need thousands of square metres of green walls to have any reductive effect, but at least we now have the tools. Some green walls are easily adaptable to the domestic market and can be fitted by amateurs. There are a few basic rules, such as going for foliage over flowers, and planting shade-loving plants at the base and sun-loving at the top, where they can catch a few rays. Plants such as ferns, Heuchera, Valeriana, Euphorbia, Ajuga and geraniums are ideal, as they are all good ground-cover plants that will grow happily as wall-cover, too. They can be laid out for all sorts of effects, from a formal and striking grid pattern to a looser, more natural look.
Late last year I was walking down Liverpool Road, just off the Holloway Road, when I thought I was having a flashback to my crazed urban jungle dream. I saw a building smothered in herbaceous plants. It was a new children's centre on the edge of the aptly named Paradise Park - a boxy building with an inspired green wall. Of course, it wasn't a dream, but it was certainly uplifting, good for my soul and hopefully a sign of things to come.