We have some very stressed out trees around here! The drought is taking its toll on the biggest members of the garden and the tiny insects are sucking all their energy too. Time to get the hose out and do some deep watering pronto. A "Ross Root Feeder" is good too but you might need to drive in some stakes (then remove them) to put the probe down into. You know how hard our soil is!
Water seeking trees, fruit trees and trees from climates where it rains in the summer are most in need. Large shrubs may also be in peril if your watering system does not water deeply.
Signs of stress are wilting, dull looking leaves, lots of leaf dropage, dead branches in the tops of the trees and sticky stuff dropping on cars and paving. The sticky stuff is honeydew from the insects that are feeding on your trees.
Please water trees at the drip line (edge of the canopy- not at the trunk) in 5-6 locations around the tree for 30 minutes per location setting the hose to percolate slowly. Regular irrigation does not water this deeply. Deep water trees twice a month in the summer and early fall.
If you do notice sticky stuff on the leaves or dripping from the trees, it is not a bad idea to give the tree a bath. Shower with the hose where the spray will reach and this will help to wash some of those insects off and clean the dust off the trees for better health. If the tree has lots of stick ooze and looks very bad consult a nursery professional for the correct pesticide to be applied. The larger tree companies i.e. Bartlett also apply these sprays.
In a few months the rain will come and do the job for us!