The role of private gardens was highlighted in a recent seminar series hosted by the Australian Institute of Landscape Architects, which stated that private residential landscapes made up almost two-thirds of Canberra's urban forest.

Bungendore-based landscape architect Jennie Curtis said overall vegetation throughout the city needed to increase over coming years to counter the heat-island effect, which she said would become ''considerably worse''.

''We need to do a lot of planting just to keep the city comfortable,'' she said. ''Right down to individual gardens, they're a key part in how we'll reduce the carbon impact in the ACT.'' Water conservation and increased food production were emphasised and Mrs Curtis said individual gardens could adapt through simple design techniques including the use of channels to direct rain water and increased variety in native and edible plants.

Her garden, on a 10-hectare property near Bywong, features drought-tolerant vegetation, mud brick walls, a large vegetable patch and the integration of animals, including chickens, alpacas and llamas.

The garden is the only Australian example to feature in a new book examining sustainability in residential settings, Designing the Sustainable Site: Integrated Design Strategies for Small Scale Sites and Residential Landscapes.

''Increasingly people are aware of designing for sustainability,'' Mrs Curtis said.

''They have generally done the home and want to see how much further they can take it.''