Question
I recenty bought a home in Lake Havasu AZ.  I have a mature orange tree that has not had past problems.  Arizona is cool now with daytime temps in the 70s.  Recently the leaves have gotten orange to yellow tips and have started falling off.  Most of the outter leaves are still there but all the inner leaves have fallen off and the tree is pretty bare.  There is some minor leaf curling.  This is an off year and it only has about 30 oranges on it.  I firtilized about a month ago and used only a half cup of citrus fertilizer.  I have not used any ironite.  Any suggestions, I'm stumped.

Bob

Answer
Dear Bob, The leaf drop is most likely due to fluctuating temperatures.  Since it has been cooler lately that is probably the reason.  Another cause could be uneven watering: has it been drier or wetter lately?  It will be especially unhappy if it stands in water, but that shouldn't be a problem in your area.  The other thing that I can think of is scale.  Scale is an unmoving insect that comes in many forms but will make hard bumps on the stems and undersides of leaves.  If you do see scale, spray with a horticultural oil once a week for several weeks until they drop off, and the condition will improve.  I might be tempted to remove the fruit a bit early, so the leaves will start growing back sooner.  Don't fertilize again until about the middle of February. At any rate, leaf drop is fairly common with citrus trees, so try to relieve any stress factors (uneven watering, scale, excess fruit) and the leaves should start to grow back.  Write back if you have further problems.  Good luck.  Melissa