If you have trees, and particularly newly planted trees (less than 3 years planted in the ground), it is vital that you water them in periods of drought. A drought is 14 days or more with insufficient quantities of rain.
The roots of newly planted trees have not grown down into the soil and cannot draw up the moisture if the water table is too low.
What are the signs?
Primarily leaves will droop from the tree, and with prolonged dry periods the leaves will be unable to function and will die. Essentially they will produce a form of bleach within the leaves. The result appears as brown leaves held on the trees during the summer months.
Drooping leaves will quickly recover, upon receipt of sufficient hydration of the tree, but once the leaves turn brown the tree can only regrow more leaves once the tree becomes rehydrated. The tiny veins in the photo show the transport vessels within the leaf which are easily visible.
Older trees can also experience drought if conditions are severe and prolonged.