Question
Hi Gary. About a year ago, I planted a Carrotwood tree which seemed to be growing well in the full sun with regualr water. But now, its leaves are starting to get yellow spots on them.  I've planted many Carrotwoods before here in Los Angeles, and they've always been easy to grow.  Could this be too much water, not enough?  Not sure what to do.  Thanks for your time.

Answer
Stan,

First, I had to look carrotwood up as I am not familiar with it.

Diagnosing leaf problems over the 'net can be daunting as you might imagine.  I may have an answer from my quick research.

Carrotwood is native to Australia.  It was first introduced to florida in the '50s and has been classified as an invasive species after escaping cultivation.  It is also reported in CA, as you are well aware, but has not become invasive.  This is possibly due to the drier climate.  This is the clue.  Some leaves on trees in a drought type of situation will develop yellowing or spotting.  

Of course this is speculation without seeing the tree.

Anyway, good luck in the garden.

Gary