Hello. I recently purchased a Washington navel orange tree for my girlfriend as a Christmas present. I've been taking care of it until she (finally) moves in. I'm a bit concerned though. While the tree looks nice and healthy, leaves have been falling off at a somewhat alarming rate. The trees is about 4.5 feet tall, the leaves are all a healthy looking green, while the newest growth near the top of the tree are bright green and waxy looking. Yet many healthy looking leaves (typically from some of the lower, smaller branches) are lying at the base of the tree every day. There are no brown or yellowing leaves on the tree at all. I have not given it any fertalizer yet as I've only had it about a month, and did not think to do so at this time. I'm certainly a novice when it comes to this, I have some plants, but never a citrus tree. Is the tree simply going through shock from being moved from the nursery to my apartment? Is there anything I can do to prevent the poor tree from losing any more leaves? Any advice would be greatly appreciated. I'd hate for my girlfriend to show up one weekend to find her beautiful orange tree completely bare. Thanks.