Water wise gardens

Gardeners have been used to turning on the tap and casually watering their plants, but can this continue?

Many plants consist of 90 per cent water and their roots have difficulties maintaining this level during hot spells.

On a single sunny day, about two litres of water are lost from every square metre of vegetation - whether grass, shrubs or even potatoes, the water loss is similar.

This is often replenished by summer rainfall and just 25mm every five to ten days is generally sufficient to keep plants growing well.

But in dry periods it has to come from reserves in the soil or from watering.