A Roof Garden by Hugo Nicolle Design

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.

Roof gardens

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
PicPost: Up on the roof

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.

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

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.

Vertical Gardens

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

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

Vertical gardens

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

Other articles in the ‘Style Counsel’ series:

Foliage Gardens

Family Gardens

Productive Gardens

Japanese Gardens

Country Gardens

Modernist Gardens

Formal Gardens

Mediterranean Gardens

Cottage gardens

Old School Gardener

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