Recently we were interviewed by a freelance writer for the Arizona Daily Star about freeze damaged Palm Trees and Citrus Trees in Tucson. After a 30 min phone interview I realized I had yet to write thoroughly on this subject and advise Tucson on what to do. (P.S. This article came out March 20th 2011 and we are happy to help get the word out there.)
In one word ..... WAIT!
The most effected palm tree is the Queens Palm. 100's if not thousands are dead and in need of removal. Even so, we advise Tucsonans to wait through the summer to see if there is any new growth. Generally if there is any green in the center it will be ok. But the amount of damage to each tree is hard to determine. California palms and Mexican fan palms are more resilient with the Mexican Fan suffering the most. After estimating trims on over 70 Palm trees at and apartment I realized that 10 or so of them would die the reason due to them being over trimmed last year. They had no dead fronds to defend themselves with and were very prone to freeze.
The citrus is a tree that I have gotten alot of calls on and turned them all down. Wait is the answer. Citrus trees respond to a light tip pruning in spring and a heavier pruning in fall. By fall you will see the new growth and see the dead allowing you to prune the tree properly. If you must prune now do so with caution. Scratch the bark and if you see any green or moisture its alive. Citrus trees by nature do not respond well to a heavy pruning so be careful.
Cactus is another story. They show damage immediately. With prickly pear and like cactus you can cut out the dead now, they are very resilient. Organ pipes and fence posts may need on or two removed from the cluster. Saguaro and barrel cactus will be fine, they may curve or change shape due to the damage.
Hope this info was helpful and wish you all a great Spring. As always check out all of our Tucson Tree Services.