I can't find information on how to care for such a tree. I live in southern California about fifty miles from San Diego in the desert country. I treat it as an outdoor plant. I use a humidity tray with it. When I water, which is once each day in the "winter" here, I water till the tray fills. By doing this am I inviting root rot? Should I be using a humidity tray on an outdoor plant?

No experience at all of this species, but I would normally use a humidity tray (for 'indoor' trees here in the UK) which is filled with gravel and the water level is such that the bottom of the pot isn't getting wet. As long as the tree isn't actaully standing in water root rot should not be an issue. The purpose of the tray is just to create a local micro climate for the plant and I guess from what you say that humidity in your area is low even at this time of year so it should be beneficial for many species

Dave

Is your plant inside or outside? Humidity trays are completely useless, a gimmick sold to those who are less experienced. A small tray of water cannot appreciably increase the humidity in a room, much less the Earth's atmosphere (if outside). I live in the Southeast U.S. and crepe myrtle grow here both as landscape and bonsai, I have them as both. Put your tree outside, make sure it is watered, and it will be OK. Crepes will not survive inside.

John

John Lee wrote: Is your plant inside or outside? Humidity trays are completely useless

Regular visitors of this forum will know I fully agree with that.
These trays are good for one purpose: catch water that drips from the pot onto your furniture, to prevent stains.
Therefore, the correct name is drip tray, not humidity tray.

OK?