JOIN USTaking greenery straight up
Given the chance to accompany a team of botanists on a plant-collecting expedition to South America, most gardeners would probably be satisfied with the experience. They wouldn’t come home and try to re-create the rain forest in Manhattan. But Michael Riley isn’t like most gardeners. Riley was eager to move beyond potted plants in a way that hadn’t yet occurred to many others.
“In the rain forest, I realised that plants didn’t need to grow in pots with labels,” said Riley, 64. “I wanted to grow plants in ways that were natural to them.” Riley attacked a corner of his living area, stripping the walls of plaster and affixing exterior-grade plywood to new and existing building studs.
On top of the plywood went bitumen roofing to protect the walls. Cork bark was then stapled over that, and plants were inserted into pockets in the cork. Sprinklers and lighting were installed overhead, trenches were put in at the base of the walls to catch water that trickled down, and pools were added in the middle of the room to increase the level of humidity.
Started as an experiment
Vertical gardens – which began as an experiment in 1988 by Patrick Blanc, a French botanist intent on creating a garden without dirt – are becoming increasingly popular in the US. Avid and aspiring gardeners, frustrated with little outdoor space, are taking another look at their walls and noticing something new: more space.
Many of the modular systems – essentially plastic trays filled with dirt and attached to a wall, with a sprinkler or drip irrigation system installed above – differ dramatically from Patrick Blanc’s living walls, which can be seen in commercial and institutional buildings around the world, including the Athenaeum hotel in London and the Musee du Quai Branly in Paris.
‘They are artificial’
On a recent visit to San Francisco to begin work on a green wall, his largest outdoor vertical garden in North America, Blanc dismissed them as artificial. Plants may grow vertically on a surface like the face of a cliff, he said, but “in nature, you don’t have vertical dirt.”
Inspired by Blanc’s work, Matthew McGregor-Mento and his wife Emma set out to build a vertical garden of their own. They attached an 8-by-10-foot aluminium frame to a wall in the entry hall, screwed waterproof sheets of PVC to the frame and tacked on two layers of matting.
Then they inserted some 400 plants – philodendrons, ivies and ferns – into holes they cut in the felt. A trough they installed along the floor collects runoff water from the irrigation system, and a pump with a filtration sponge sends it back up the wall. Timers control the watering, which happens four times a day. The design, which they devised with the help of a horticulturist friend, was based on Blanc’s system and on research they had done online.
“Building a vertical wall is about as difficult as painting a room.” Others have found it more challenging. Peter Kastan had never grown anything when he decided to install a vertical garden in a friend’s loft.
The apartment, which his friend offered to him as a laboratory since it was vacant and he couldn’t rent it, had abundant light and high ceilings, and Kastan, after reading about Blanc’s living gardens online, thought it would be an ideal environment. He bought 650 plants, including bromeliads, hoyas, begonias and ferns, favouring those that were local and “the most interesting to look at,” he said. Kastan bought most of the materials from local hardware stores or online suppliers.
It took a lot of work to get the irrigation, the lighting and the plants right. The first month, he lost several plants near the bottom of the wall, where water was collecting. He realised then that some plants were getting too much water and needed to be moved a different spot on the wall; others he had to get rid of. Even professional gardeners sometimes have trouble with their first living wall.
Marguerite Wells, co-owner of a nursery said she tries to steer people away from vertical gardens.“People want green bling,” Wells said. “People think, ‘It looks beautiful and perfect, and I want something beautiful and perfect in my life.”’ But vertical gardens can’t be watered with a hose or ignored for long stretches of time, she noted, and won’t tolerate certain plants.
Not just a green wall
Inevitably, the irrigation stops working, she said. And within a few days of any malfunction, plants begin to die. Amelia Lima, a landscape designer in San Diego, encountered the most basic problem when she decided to turn the 40-foot wall in her backyard into a vertical garden. At first, she tried hanging plants and art on the wall, which faced the picture windows in her living room and kitchen, but it looked drab. Then she found a landscape architect who had worked with Patrick Blanc on a project in Brazil and hired him to help. But halfway through the project, she realised she had forgotten something essential: a water source. “People think it’s a green wall,” Lima said, as in, “you hang a picture on the wall and it’s done.” But there’s a lot more to it than that, she added: “There’s construction, watering – you’re making a garden.”
Floor (to ceiling) plan
Vertical gardens are heavy, and not every wall is strong enough to support one. Check with a carpenter or your landlord to make sure the designated wall can handle the load.
When selecting a spot for your living wall, make sure the area gets plenty of light. The best light is natural, but you will also need to install artificial lighting.
Custom installations require a frame that can be attached to the wall, a waterproof barrier to protect the wall, a surface material like felt or cork to hold the plants in place and an irrigation system with PVC or polyethylene tubing and a submersible pump (the kind found in aquarium shops).Ready-made vertical garden kits have small containers angled to hold dirt and can be watered manually.
After you plant your cuttings in the dirt, you’ll need to let them grow horizontally for several months so they develop a strong root structure.
Each wall has different requirements, depending on its light and plants (talk to a local nursery or green-roof specialist about the best plants for your wall), but many people water their vertical gardens three times a day for eight to 10 minutes. You will need to add fertiliser to the water to make sure the plants get their necessary nutrients.