Problem with my purple Orchid Tree (pics)

[pion]

Hello,

I'm having a problem with my purple orchid tree (Bauhinia variegata, as best I can tell). I live in Phoenix, AZ. It barely grew any flowers this year and many of the leaves are browning. Here is the tree:

http://i.imgur.com/GBGs4.jpg

This time of year, it would normally be much lusher--notice the "dead" branches along the outside with no leaves.

Here is an example of a leaf: http://i.imgur.com/A3Ouv.jpg

It has been getting enough water (the same amount I always give--flood irrigation). There was an overnight frost here a few months back which damaged some of my bushes. However, the problem with the orchid tree didn't appear to coincide with the frost. There don't appear to be any bugs on it that I can see. Some palms have recently sprouted under it but I can't imagine that is a problem. I read it could be a potassium deficiency so I am going to fertilize it this weekend. Beyond that, I'm at a loss for what to do. I really like this tree and I'd hate to lose it.

Thanks for any advice anyone can offer

 

[Urban Forester]

Exterior twig dieback like that oftens indicates a root issue. The leaf tissue also indicates lack of water movement. I would call an ISA Arborist and have him do a root crown excavation. It would seem that if the tree was fine up until now, there could be a girdling root that has created a pressure on the trunk slowing water movement.

 

[beastmaster]

How old is the tree? I see a lot of old orchid trees start to decline. It also looks a lot like phytophthora, and it has similar symptoms as girdling roots, but is a death sentence.
Has it been a wet year for you guys? Drainage issues can cause phytophthora.

 

[pion]

Thanks for the suggestions guys. I actually just went out to water it and I noticed a bunch of new growth at all the tips of the branches. I think it may have just been the frost after all, and I just didn't notice the damage right away. Thanks again.