Innovations don’t come up often in gardening. A couple of years ago, at big
shows such as Chelsea and Hampton Court, visitors clustered around show
gardens that demonstrated how to transform sterile surfaces such as shed
roofs into flowery meads. This year, lush, leafy wall coverings caused a
stir: some uniformly green, others making tapestries of maroons, reds, pinks
and lime greens.
As well as providing beautiful patterns and textures, cladding a building with
plants is an ecofriendly option.
Green walls can be excellent insulators, reducing the temperature fluctuation
of a building by as much as 50% - which means less need for heating or air
conditioning, so lower carbon emissions. The plants act as pollution and
noise filters, and can reduce localised flooding, as they absorb rainwater
rather than letting it run straight into the drains. They also provide food
and shelter for insects and birds, increasing biodiversity.
As anyone with Virginia creeper or ivy on their walls will know, climbers also
tick all these environmental boxes, but living walls (as they are also
called) have the potential for a much greater variety of plants and don’t
need ground soil. That makes them just the ticket for anyone with limited
space - a balcony, courtyard or paved basement, say - who is looking for
something lush and more interesting to look at than a featureless wall.
Patrick Blanc, an entrepreneurial French scientist, pioneered this kind of
planting in the 1990s with his Murs Végétals - expanses of jungly-leaved and
flowering plants that spring out of the facades of various museums, hotels
and corporate HQs in France (www. verticalgardenpatrickblanc.com). There are
examples in Brussels and Spain, and at the French embassy in Delhi, while
the first one to Blanc’s design in this country will be completed later this
year on the Leamouth Peninsula, in London’s Docklands. His book, The
Vertical Garden, has just been published (WW Norton £32).
Blanc got the idea when he observed that many plants in tropical rainforests
and temperate mountainous areas survive without access to soil: in Malaysia,
about 2,500 of the 8,000 known species grow this way. The hydroponic system
he devised - consisting of a metal frame fixed to the building facade,
holding a PVC liner with a felt layer on top, into which the plants root -
relies on a constant supply of water and nutrients. His exact method is a
trade secret, but Mark Gregory (01932 569169, www.landformconsultants.co.uk
), who made a wall of heucheras, sedums, euphorbias and ferns for his
gold-medal Chelsea Flower Show garden for the Children’s Society this year,
reckons it’s only a matter of time before the technology is widely
available.
In the meantime, designers and garden-makers have been beavering away,
devising their own versions - you can see public examples in London at New
Street Square, in the City, at the O2 Arena and at Paradise Park Children’s
Centre, in Islington.
Earlier this year, the landscape designer Mark Laurence launched a hydroponic
system (www.biotecture.uk.com )
that he says requires a sixth of the water used by Blanc’s vertical gardens.
The rooting medium is horticultural rock wool, a mineral-based man-made
material that holds moisture efficiently. Laurence is now giving quotes for
large private spaces as well as commercial buildings. It’s an expensive
option if you’re installing it to decorate just a few square feet of wall
(about £3,000 for an area between 36sq ft and 90sq ft, fully planted and
installed), but becomes much more manageable if it’s part of the building
fabric, either in a new construction or a refurbishment.
Anjana Devoy and her husband, David, have been working with a team of
designers to create a hydroponic green wall for the upper-storey “hide” - a
standalone room that doubles as a viewing platform and a home cinema - at
their new home overlooking Richmond Park, Surrey. Shown Blanc’s walls by
Thomas Godwin, a garden designer with whom they are working, they were
knocked out by the concept, even making trips to Paris to see some of them
in situ. “We loved the idea, but felt we wanted one that was less jungly and
had swirls of colours and textures,” Anjana says.
Nearly a year on, two green walls have just been planted up, with diagonal
swathes of carex, heucheras, ber-genias, campanulas and purple sedum on the
sunny side and shade-lovers such as ferns and euphorbias on the north.
“Thomas chose low-maintenance plants with colours that link to the vegetation
of the park,” Anjana says. The 85-sq-ft walls - each one a framework of
interlocking stainless-steel cages, lined with horticultural wool and filled
with volcanic pebbles - cost about £15,000 each to build and plant up.
Further costs will include the pump for the irrigation (using rainwater,
which is flushed down the wall twice a day) and added nutrients. The Devoys,
who were formerly barristers, have been so impressed by the potential of
these walls, they are setting up a company with Godwin to design and install
their prototype (07951 957067, www.verticallandscapes.co.uk
).
A different solution, already established in Britain, is a soil-based modular
system, ELT Living Walls, which was developed in Canada and is available
from Aldingbourne Nurseries, Sussex (01243 544941). The polyethylene panels,
which are divided into compartments, are 20in by 20in, so you can experiment
with a small area first, or install two or three differently planted panels.
A single unplanted module costs £39.50, though the price comes down when you
buy in bulk. For more information, visit www.eltlivingwalls.com
.
Nicola Giuggioli, co-founder, with his sister Livia and her husband, the actor
Colin Firth, of Eco Age (www.eco-age.com
), a smart eco-shop in Chiswick, west London, chose this modular system to
clad the upper floors of the building. Installed at the beginning of the
year at a cost of about £12,000, it had some teething problems with
irrigation, but these have been rectified - the drip system now runs for
half an hour each day in summer (less often at other seasons) on an
automatic timer.
“It is a really good way of insulating a building - and makes a spectacular
facade,” Giuggioli says. He says they looked at various systems, but chose
this one because of its “modularity” - if there is a problem with any of the
plants, you simply take out a panel. They selected six varieties of fern and
two festuca grasses, as they wanted the walls to be low-maintenance and stay
green all year.
The shop will organise installation of ready-planted panels anywhere in the
country; alternatively, you can order the panels direct through Aldingbourne
Nurseries, then plant and erect them yourself. “Any competent DIYer should
be able to put them up,” says Doug McIntyre, senior marketing manager at
Aldingbourne.
Gregory is creating a wall with Joe Swift, the garden designer and Gardeners’
World presenter, that uses compost rather than rock wool and is planted with
herbs. The 3ft-wide shelves are secured at 45 degrees to the wall for
drainage, with vertical boards forming the compartments that hold the
compost. Weed-suppressant fabric is stapled across the front of the boards,
with holes cut into it for the plants, and the whole thing is secured with
chicken wire.
“Use plants that will grow naturally in vertical situations, like ferns and
aubrieta,” Gregory advises. “Put the ones that like the driest conditions at
the top and the ones that prefer wetter, shadier conditions at the bottom.
And be prepared for it to look a bit bare until the plants knit together.” Materials
for a 6ft x 3ft unit would cost about £80, so you can afford to experiment
with different planting schemes. Just don’t let the compost dry out, or your
living wall may come tumbling down.
