All trees are likely to experience a drought at least once in their lifetime — especially those in Australia. However, while a tree may survive one or even several droughts over a few years, the damage eventually mounts up. The cumulative damage of several droughts may kill a tree in time — unless you can spot the warning signs early.

Check the Leaves

If you are new to watering trees, especially during hot spells, it is important that you know what drought stress looks like. In the early stages, a dehydrated tree's leaves will lose their colour and become limp. Obviously, this is a good time to intervene. However, if you act too late or water your tree incorrectly, your tree will soon begin to display advanced symptoms of drought stress.

Brown, brittle leaves that are curling at the edges are a sign of advanced drought stress. At this point, even if you give your tree plenty of water, your tree may not make it. Sick trees can no longer fight off diseases and pests as effectively as they once did. Unfortunately for tree owners, you may need to wait until next spring to find out if your tree will survive or not. If it does not survive, you may need to call a tree removalist to take care of it.

The Science of Drought Damage

Trees need more than just water to survive. They also need to take in carbon dioxide via photosynthesis, which they then turn into oxygen and carbohydrates. A tree needs both methods of sustenance to work together to stay alive. During a drought, however, this becomes a problem.

In order to take in enough light and carbon dioxide to create food, a tree needs to open its stomata. These tiny pores are located in the leaves, and they act as doorways, allowing a tree to take in light and carbon dioxide. Unfortunately, during a long spell without water, tree's close their stomata to prevent their remaining water supply from evaporating.

Without their ability to photosynthesize food, trees turn to the carbohydrates stored in their roots. If there is plenty of food stored in a drought-stressed tree's roots, for instance, that food storage should see the tree through until spring when it can replenish its supply. Should a tree not have enough food to make it to next spring, it could well die.

Drought stress can be avoided providing you water your trees correctly and frequently enough.

However, if your tree doesn't seem to be recovering from a recent spell of hot weather and underwatering, you may need to remove it. Otherwise, once it dies, it will become brittle and weak. This could be deadly when the next storm rolls through.