How do I... build a vertical garden?
"We have an ugly back fence that we would like to disguise with a vertical garden but don't know where to start. Any suggestions?"
This guide to building your own vertical garden was contributed by freelance writer Rachel Sullivan. An avid gardener, Rachel has shared her experience of building her own vertical garden to help us answer this week's reader question. Thanks Rachel!With backyards shrinking vertical gardens are a great way to create a lush, productive garden that doesn't take up any space. Depending on the aspect of the garden and its exposure to sun and wind, it may be possible to create a salad garden with leafy greens and herbs. Alternately, visual impact and a feeling of both depth and intimacy can be created by planting combinations of foilage plants.
The concept started with French plant scientist Patrick Blanc, who was inspired by the way plants grow on cliff faces and on trees in rainforests. He saw the potential for greening urban spaces by covering walls and other structures with carefully selected plants. His work is now seen all over the world, from Qantas lounges in Australia, shopping centres, hotels and office buildings in Asia, entire buildings in Europe, and even road overpasses in his native France.
Many other vertical landscapers have followed in his footsteps and some of their most recent works can be seen - and used for inspiration - in the recently-released book Facade Greenery by Chris van Uffelen.
There are many off-the-shelf modular systems that can be found with a quick Google search for 'vertical gardens', or for added piece of mind professional landscapers can tailor a garden to your site.
Do it yourself.There is also a DIY option. In an interview for Handyman magazine in October 2010, landscape designer Brendan Moar recommends commissioning a steel fabricator to make a frame from reo mesh: for example 1500 x 1800 x 100mm.
"Then make up a liner of geotextile fabric to fit inside the frame to hold the soil, securing it with garden ties," he explains.Award-winning landscape designer Philip Johnson, from Philip Johnson Sustainable Landscapes demonstrates another method in this video for the Garden Gurus.
After checking engineering requirements associated with attaching a structure to a wall or fence, he suggests using lightweight materials including recycled HDPE plastic sheet for the backboard (available from DesignFlow). The growing media is made up of four layers: weedmat (available from any hardware store), felt, weedmat and felt.
The felt is made from recycled materials and can be purchased from JJ Davies. It is all attached to the backboard using a staple gun, and a dripline is also inserted between the layers to ensure everything gets watered. Slits are then cut in the fabric and plants inserted with some soil and then stapled into place.
Putting it to the test.I used this method to build a vertical garden of my own against our ugly back fence but mistakenly ordered recycled PVC instead of HDPE, which was too hard for our staples to penetrate (and also one of the most environmentally damaging plastics available).
We were advised to make the holes for the screws attaching our garden to its frame (we couldn't attach it directly to the fence so built a frame) slightly larger than the size of the screw, capped with a washer. This allows the plastic to expand and contract as the temperature changes during the year without warping or otherwise being pulled out of share. Putting a gutter at the bottom will collect any excess runoff which can then be recycled or directed elsewhere in the garden.
When it came to choosing plants, we were mindful of the amount of shade covering most of the garden, so for colour we used lots of unusual bromeliads (which are jungle epiphytes and well suited to a green wall), and can be cheaply purchased on ebay, while for texture we opted for lots of different ferns and other shade-tolerant species whose natural habitat is cliff faces. Finally in the sunniest patch we used a range of succulents for contrast.
Obviously the larger plants you put in the green wall, the greater the impact from the start. but they do still need some room to grow. Seaweed-based fertiliser and other plant appropriate nutrients will ensure they take off, and hopefully create a living sculpture that is not only a pleasure to look at but has lots of other environmental benefits as well.
The finished product.