WE HAVE no choice but to start thinking seriously about the way we use water in the garden. Most plants struggle to keep up with high temperatures and rapid evaporation rates.
It is the shallow-rooted exotic plants that suffer most of all.
Most vulnerable are rhododendrons, azaleas, pieris and of course many young conifers.
Too often we tend to virtually ignore these spring-flowering or lushly growing plants now that they are nowhere near as flamboyant as they were a few months back.
When they become neglected and sparsely watered during hot weather, exotic evergreens cannot signal stress by allowing their leaves to wilt.
The most obvious signs appear long after the heat and dry conditions have past. That's when they die back from leaf tips or slowly turn brown. By this time it is a bit too late to do something and if the plants survive they may take years to fully recover.
One answer is deep mulching, but even this can be tricky if only superficial watering is carried out.
In fact water-stress can be made worse by casually hand-watering, applying just enough to wet the surface and mulching materials.
This induces the roots of thirsty plants to grow and concentrate closer to the surface of the soil just beneath the mulch and become even more vulnerable.
We get fooled because this layer of moist material gives the impression that the ground below this is also moist when it could be bone dry.
We have to encourage roots to delve deeply downwards where there is a far better chance of moisture being retained for a longer period.
So by all means mulch generously, but keep the stuff away from stems; otherwise many shrubs and trees can develop collar rot as the lower bark goes soft and mouldy.
After mulching plants, start pouring in water very slowly so it can soak in deeply, right down to the subsoil. Remember, dry soil in summer - especially sandy soil - becomes water-repellent when dry.
A deep soaking needs to be carried out only two or three times during the hottest part of summer.
That's enough to keep most plants healthy, growing strongly and forming plenty of flower and growth buds for a flying start in spring and early summer.
However, let's also look at the toughest, most drought-resistant plants. These are the ones with deep searching roots. They can also withstand hot, breezy weather and a few are able to survive and grow right from the start particularly if planted in autumn, winter or early spring - without ever needing to be watered.
I've just been openly gloating about what was once a very dry, hungry, exposed bank.
About five years ago I somewhat desperately planted a selection of very tough plants.
Previously it had proved so dry that almost every exotic I tried died within a year.
That's when I went native and I'm so glad I did. I can't believe how successful these beautiful plants have been.
They were planted in late winter and since then have never been watered.
They had to survive on normal rainfall yet are now absolutely thriving in miserable, impoverished acidic soil.
I decided to grow a privacy screen, so in went a row of tea-trees (Leptospermum nitidum Copper Sheen). They were only a few centimetres tall when I planted them from tubes. Already they have grown well over two metres high.
I clip them back a little after flowering so they have also become thick and dense.
They are well-named because the foliage is a wonderful coppery-bronze with a hint of purple. And the flowers come in thousands packed together like marvellous white clouds. Bumble bees adore them.
Just in front on an even drier, more exposed part of the bank grows a selection of Tasmanian native grasses.
The huge, clumps of Poa rodwayi are well over one metre in height with pale leaves, greenish flowers and superb seed heads. About the end of April I'll cut these clumps back hard and within weeks they'll be sprouting again.
It is also an easy task to pull one or two of the clumps apart in order to create lots of new divisions for immediate planting.
And these amazing, drought-proof plants never look back.
