A Roof Garden by Hugo Nicolle Design
This ‘snippet on style’ focuses on gardening above ground – roof gardens (including ‘green roofs’), balconies and vertical gardens. Growing plants above ground has been going on for centuries: e.g. the ziggurats of ancient Mesopotamia and the Villa of the Mysteries in Roman Pompeii.
A roof garden is any garden on the roof of a building. Roof gardens can be of ornamental value – especially in urban locations where no ground level garden is available. They can also play a part in:
- providing food – Trent University has a rooftop garden which provides food to the student café and local citizens
- temperature control – plants can help to reduce heat absorption on buildings (so reducing the need for artificial air conditioning), achieving a cooling of the environment by between 3.6 and 11.3 degrees Celsius
- controlling and harvesting rain water run off – where urban areas are increasingly hard – surfaced, roof gardens can delay peak run off and so help to prevent flooding, as well as retaining moisture for later use by the plants.
- adding to the appearance of a building
- providing habitats or corridors for wildlife
- recreational opportunities
A great place to grow vegetables
Cultivating food on the rooftops of buildings is sometimes referred to as rooftop farming, and is usually done using special systems such as hydroponics, aeroponics/air-dynaponics or in containers. These systems can also help to reduce the stress on the roof that would otherwise have to carry a depth of soil over its whole surface. Sometimes as well as using the space on a roof, additional growing areas are added as ‘air bridges’ between buildings.
Roof Gardens are as old as the hills- this one’s in Assisi, Italy
A modern roof garden by Marigreen Ltd.
Rooftop veggy growing, Jamaican style
Formal raised beds on the roof
The Woodland Garden at the Roof Gardens Centre, Kensington, England
A densely planted roof garden by Bridgman.co.uk
The roof garden designed by Sir Geoffrey Jellicoe
Penthouse roof garden, New York, via Rezpector de Blanco
One person’s vision of how rooftop New York could look
In creating a roof garden there are several important factors to consider:
primarily the bearing capacity of the roof structure – this can be designed to be minimal, so really creating a ‘green roof’ (bearing about 100-300kgs per square metre) or ‘stepable’ (bearing over 300kgs per square metre)
prevention of roots and water penetrating the roof structure
the inclination of the roof (this should not exceed 30°)
the altitude of any attic, etc.
Roof gardens are likely to feature more and more in major cities – 80% of Singapore residents voted for more roof gardens in the City’s future plans. The containers/planters on a roof garden may be designed for a variety of functions and vary greatly in depth to satisfy aesthetic and recreational purposes. These planters can hold a range of ornamental plants: anything from trees, shrubs, vines, or an assortment of flowers. Where aesthetics and recreation are the priority roof gardens may not provide the environmental and energy benefits of a green roof.
A ‘green roof’ made up of various succulent plants
Once again you need to be aware of how much weight your balcony can take, so seek structural engineer or architect advice if you’re unsure. Balconies can be used for both ornamental or food plants, but it’s worth thinking about your layout before you start. To maximise growing space, suspend window boxes along the balcony edges, place soil-warming terracotta planters in the sunniest patches, and put lean-to shelves against the wall to accommodate extra pots. Here’s a video about setting up a balcony garden using permaculture principles.
A smart balcony garden in Mumbai
A balcony with a selection of pots for growing herbs and food can look attractive
For those who live in small apartments with little space, ‘square foot gardening’, or (when even less space is available) vertical gardens or ‘living walls’ can be a solution. These use much less space than traditional gardening – square foot gardening is said to use 20% of the space of conventional rows and ten times more produce can be generated from vertical gardens. These also encourage environmentally responsible practices – eliminating tilling, reducing or eliminating pesticides, and weeding, and encouraging the recycling of wastes through composting. Some of the most familiar vertical gardens are called ‘living walls’ – a concept where low growing and small plants are placed into a matrix which is then fixed to a wall. Such designs can be immense in size, covering the entire sides of buildings. They are also increasingly being used inside building spaces, such as foyers and receptions, to create a contemporary and eco-friendly ambiance. There is a trend towards more living walls in people’s homes. This has led to many companies now providing products which create a vertical garden to liven up the side of a house or patio, and platforms of pots which can be planted with herbs and vegetables on a balcony. Some of my own articles feature the use of old pallets for vertical planters and these too can be considered as ‘living walls’ and are a useful addition to conventional ground level gardens as well as homes which lack much outside space.
There are clear advantages to vertical gardens:
creating growing space where normal ground level space is restricted
offering a green outlook to those who want to avoid views of concrete and bricks
creating spaces which are beneficial to both mental and physical health
making it easy to grow food plants such as herbs and salads
A colourful vertical garden
A simple ‘flower wall’ using Morning Glory
Sources and links:
Wikipedia – roof gardens
Wikipedia – green roofs
RHS- roof gardens and balconies
The Roof Gardens- Kensington
6 green roofs you can relate to
How to design a roof garden
A garden on your balcony
Balcony Garden and rooftop garden ideas
10 Inspiring Balcony Gardens
Green Roof and Green Wall ona Sydney high rise building – David Eugene