thisplace.com.au - How to Identify Water Efficient Plants

Choosing the correct plants is a vital aspect of establishing a water efficient garden. There are many beautiful plants that are well suited to hot climates such as ours.

Some Australian native plants, as well as some of the plants from the Mediterranean, South Africa or the west coast of America are adapted to survive dry conditions. These plants survive dry conditions by:

storing water,
reducing water loss or
accessing water deep in the soil

When you are choosing new plants for your garden please look for the following features!

Small Leaves

Small leaves are an adaptation to dry and arid conditions. Most water efficient plants have small, tough leaves, often rounded or needle-like to minimise surface area.

Light Leaf Colours

Foliage colour is a good indicator of plant water usage. High water use plants which have developed in shady areas have a soft dark green surface. Water efficient plants tend to have a light green, blue-green or grey-green foliage which reflects the light and keeps the leaf cooler thus reducing transpiration.

Hairy Leaves

Hairy leaves are an indication of water efficiency. Hairs surrounding the plant pores act like a windbreak, slowing down air movement over the pores and thereby reducing moisture loss.

Tough Surface

Water efficient plants have a tough, hard and sometimes waxy surface to there leaves. While most moisture loss is through the pores, there is some loss through the actual leaf surface. Australian native plants such as Callestemon, Melaleuca and Eucalyptus have these tough surfaces as do other species of plants like Ceanothus, Rhaphiolepis, Pyracantha and Elaegnus.

Strong Internal Structure

Tender plants wilt in the heat when they cannot take up water fast enough to replace that lost by transpiration. Though they recover from short periods of wilting, if it is prolonged the structure of the plant can be damaged. Water efficient plants have a strong internal skeleton which prevents this wilting. This combined with reduced transpiration ensure they can survive extended periods of heat stress.

Protected "Pores"

The leaves of plants contain small pore like openings called stomata through which most of the moisture is lost through transpiration.

They can be likened to the sweat pores in our skin.

Water efficient plants have fewer of these pores or protect them to minimise water loss. Water efficient plants also have most of their stomata on the underside of the leaves where they are less exposed to the sun and wind.

Internal Water Sources

Water may be stored in many different parts of a plant including:

The trunk
A swollen root system
In the leaves

Some examples include:

Trunk - Boabab Tree and Barrel Cacti
Root System - Kurrajong
Leaves - Pigface, Crassula and Kalanchoe

Deep Root Systems

Many plants can develop very deep root systems which enable them to reach down into the ground in the search for water. Some of the native plants develop these extensive root systems which tap into the water table, so that once they are established they need no further supplementary watering.

Source: WaterWise How To Identify Water Efficient Plants at a Glance.