Question
This hedge is in Tampa Fl. It is dropping leaves on the lower levels. Some
leaves have brown patches. The top of the hedge seems heathly and green.
Right now it is in certain areas and has not spread over the entire hedge. I
found I have been over watering. It is on a drip lie and was receiving 30
minutes drip every night. I have changed this to once a week. Also I noticed
two places where a large slightly spongy brown ball has grown out of the
trunk of some of the plants.

Answer
Hi Elizabeth,
Ficus

Whitefly is causing extensive damage on ficus hedges and trees in Dade County.  Leaves yellow and hedges and trees become bare if not treated.  Treat with Organocide at weekly intervals for 3 weeks to give control.  Trees and hedges grow back if treated.  Ficus benjamina is a favored host but this whitefly also attacks other ficus.  As you do not say which ficus I believe this to be general information to the different varieties/

I also found this site to be interesting info for you.  kathy

miami-dade.ifas.ufl.edu/old/programs/urbanhort/publications/ Caulkins%20pdf/Calkins%2030%20Hedges.pdf