Answer: Arizona cypress are reputed to be hardy, trouble-free trees. They are occasionally subject to canker diseases, but that is usually a problem in the more humid southeast. And the symptoms include a general dieback of branches throughout the tree, not broken off tips. My first thought is whether you might have deer "browsing" on your trees. Deer will chew off the tips of branches. Is this a possibility? If so, there are some things you can do to try to deter them. You might consider taking a sample of the damage to a local nursery for identification. Or contact your local Extension agent about problems with cypress in your region. Their number is 209/468-2085.
Q&A Library Searching Tips