Sue Fisher - Growing Up the Wall: How to Grow Food in Vertical Places, On Roofs, and In Small Spaces

B&Qs Vertical Allotment at the 2011 Chelsea Flower Show.

Growing crops on the vertical and on roofs is a fantastic solution for space-hungry individuals, groups and communities. Whether youre an apartment-dweller with a wall, windowsill, balcony or small flat roof at your disposal, a school with nothing but a tarmac playground, or a group with just a paved courtyard in your community centre, this book is for you. Even if you have a garden already, there are benefits to be gained from growing crops in the wonderfully beneficial microclimate of a sheltered wall or fence. The rewards are many: delighting the taste buds with fresh, still sun-warmed tomatoes or strawberries, and the joy of harvesting ones own crops without any food miles whatsoever. Perhaps most of all, the sheer deep-down satisfaction of not just growing plants in hitherto impossible spots, bringing nature back into stark and bare places, but beauty with a practical purpose.

While living walls are a recent development, conceived as a combination of new technology and increased pressure on outdoor space, the concept of green roofs has actually been around for thousands of years. Traditional homes in parts of the world that experience bitterly cold winters, such as Scandinavia and Iceland, often had thick turf roofs because of their excellent insulating properties, as well as ease of maintenance. The Hanging Gardens of Babylon, built around 600 BC , was the first recorded green roof garden, the great arcaded structure built with ascending terraces, roofed with bundles of reeds, layers of brick tiles and thick sheets of lead to waterproof the rooms below.

Creating growing spaces on the vertical using hanging baskets, window boxes and balcony gardens is a technique that has been in use for centuries. However, the concept of extending growing areas over the whole roof or wall, although relatively new, is edging nearer the centre of mainstream gardening. The relentless increase in population and urban growth, coupled with increased environmental awareness and the threat of climate change, has inspired a real sea change in the approach to buildings and development. Vertical and roof growing is made possible with modern materials such as highly efficient waterproofing membranes, irrigation systems and lightweight growing media, to enable the greening of buildings on a grand scale. And while government policies vary around the world, of course, the change in attitudes that can be seen in many countries is immensely heartening.

To give just a few examples: in the UK, living (green) roofs and walls such as those at the O2 Arena, several shopping centres and the South Downs water treatment centre, have become major features of prominent new developments, both public and commercial, and are often a major consideration in allowing planning permission to be granted. Some states in North America, and some Canadian cities, offer tax incentives and subsidies for these features. In cities such as Copenhagen and several in Switzerland, it is now law for all roofs from flat up to a 30-degree slope to be planted. While in the main it is these large-scale commercial developments that grab the headlines, there are many inspirational small-scale features benefiting from spin-offs of the same technology. And, while commercial projects are bound to an exceptionally high standard in terms of quality of materials, on a domestic scale there is more scope for experimentation and DIY with simple, affordable projects using both new and recycled materials.