Minister for Territory and Municipal Services Shane Rattenbury said tankers capable of carrying 10,000 litres would draw water from Canberra's lakes and soak each tree once a month until April.

But Mr Rattenbury called on Canberrans to be aware of young trees near their homes and to water plants regularly during warm periods.

"An eight-litre bucket of water once a week could provide enough supplementary water for young trees to survive the summer climate," he said.

"A larger tree of over five metres may require several buckets once a week, during the cool of the morning or evening. The water should be applied slowly, close to the tree's trunk."

Mr Rattenbury said second-class water from baths or washing machines could be used to water young plants, if environmentally friendly shampoos or detergents were used.

The government-led watering program will use GPS and spatial technology to map each young tree in Canberra so contractors can easily find them.

Mr Rattenbury said the program proved a success last summer, whenonly 1 per cent of young trees across Canberra were lost due to hot and dry conditions.

"Weekly progress reports provided by the contractors allow us to collate a wide range of information such as vandalised or missing trees, overall tree health and maintenance requirements," he said.

"The reports also act as a watering diary to provide us with specific details on daily watering activities, such as the number of trees watered and the volume of water used in the process.

"This will allow us to evaluate progress and reallocate resources if required."