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.
For a domestic green wall system, see www.eltlivingwalls.com,
a Canadian company that supplies plastic walling modules. Its UK franchise
is Aldingbourne Nurseries, Church Road, Aldingbourne, West Sussex (01243
544941). For more inspiration, visit
www.verticalgardenpatrickblanc.com, www.sky-garden.co.uk/pages/living-walls.php
and www.d4b.org.uk/caseStudies/paradisePark/index.asp
