Upwardly Greening Up

‘Going green' is extending into new and unusual situations. In pursuance of ‘urban agriculture', people living in cities and towns have been encouraged to give serious consideration to installing a kitchen garden on balconies, flat roofs and other suitable high spaces. This initiative should be seen in light with statisticians' predictions suggesting that cities are more likely than rural areas to suffer the effects of any future food shortages. Now ‘greening up' is extending rapidly into country towns and villages - but not necessarily in order to produce food!

Recognition is growing about the ways in which human health is linked to biodiversity. At the same time, we are aware of the fact that many species of wildlife are in decline to the point of being seriously endangered - even driven to extinction.

Over thousands of years, hundreds and hundreds of species of wildlife have become extinct - but until modern times, this was almost always a natural process rather than one driven by humankind's abuse of the planet. We have been, and continue to be, responsible for the destruction of habitats. The Rain Forest is a supreme example that immediately springs to mind but we have a lot to answer for in this country too. We have been - and continue to be - the cause, directly and indirectly, for the loss of hundreds of our native species - birds, mammals and plants.

In order to benefit endangered wildlife, more and more people are creating ‘Green Roofs' and planting them up with native wildflowers attractive to bees and butterflies. Green Roofs have other environmental benefits too because they absorb carbon - added to which they are excellent insulation and help to maintain the property at an even temperature by keeping the heat in during the winter - and out during the summer. An infinitely healthier option - and much better for the environment - than air conditioning!
Anyone considering giving their house - garage, shed or other outbuilding - a ‘Green Roof' will need to check that the structure of the building is suitable. The weight of the garden will largely depend on the depth and type of substrate - but it should be borne in mind that the weight can increase dramatically after torrential rain or a heavy fall of snow!

Very much depending on the structure, some flat roofs can be planted quite extensively and even used to grow large shrubs and trees. Although planting options are more restricted in the case of pitched roofs, they nevertheless make a valuable environmental contribution. Another important factor is access: an ordinary ladder that can be moved around as needed would suffice - but gardeners keen to combine functionality with funkiness and appearance may want to consider purpose-made steps. Depending on the location, a wrought iron spiral staircase, a rough bark-clad ladder or other innovative design could add to an already interesting feature

This year the RHS Hampton Court Palace Flower Show devoted an area to Small Sustainable Gardens for the first time. Judged the best overall sustainable garden, ‘The Rain Chain' was designed by ex-Hadlow student Wendy Allen and sponsored jointly by the college and Westgate Joinery. It incorporated a Green Roof designed to cope with the sort of flash floods that are occurring with increasing regularity and was capable of absorbing an estimated 70% of rainfall. Water not absorbed by the roof drained down The Rain Chain - which replaced a conventional downpipe - into the Rain Garden where it gradually soaked away. (It really worked too - as demonstrated during heavy showers at Hampton Court!)

The Green Roof was planted with drought tolerant plants that benefit butterflies, bees and other forms of wildlife, thus increasing the biodiversity needed to secure a sustainable future for threatened species. Plants in the Rain Garden were specifically selected for their ability to tolerate short periods of both waterlog and drought - and water storage was covered by the inclusion of a water butt. Carrying ‘sustainability' further, the timber-clad house wall that formed the backcloth was especially designed to be reassembled as a summerhouse - complete with a Green Roof - after the show.

Construction materials utilised in the garden were largely recycled and included railway lines and rusted steel used to make the planters and water butt. The practical parking space in the garden was occupied by a small, environmentally friendly electric car. All the surfaces within the garden were permeable, thus reducing water run-off. (Since October 2008, it has been necessary to obtain planning permission before covering a front over a front garden with any impermeable material. The legislation is intended to reduce flooding.)

Ask any of the many Hadlow graduates who have won medals at RHS shows and they will all agree that the designs of very few show gardens are entirely suitable, for a variety of reasons, for the average family garden. What they very successfully do, however, is give gardeners fresh and innovative ideas they can adapt to suit individual circumstances. Many of the ideas featured in The Rain Chain could certainly be adapted in any number of situations.
(Hadlow College offers career (degree and HND) and recreational courses in Garden Design. Telephone 0500 551434.

www.hadlow.ac.uk