I have a weekend home located 5 miles from the conjunction of GA, TN, and NC state lines. I have an Arizona cypress, 12′ tall, 10′ base spread, in the ground for seven years. The tips of sub-branches are turning brown. The tree looks otherwise healthy. What’s wrong, if anything? What should I do?
The Gardener’s Answer
Hello, Bill: Arizona cypress (Cupressus arizonica), hence its name, is native to central and southern Arizona. Once established, after 2-3 years it is very drought and heat tolerant, but this evergreen is subject to sunscald, which may be what has happened. This ornamental with bluish foliage is perfectly hardy to your region but does seem to be shorter lived in the southeast. It does not typically have a lot of insect or disease problems in its native habitat assuming that it is growing in full sun (six hours); it is, however, more susceptible to canker when grown in areas of high humidity (such as the southeast). Too much moisture can be a problem so if it is planted in a space where the soil does not drain well this can become an issue. When did you first notice the browning? If it was green all winter and has now turned brown during the summer months we can rule out winter damage. It can take some time for plant material to show winter damage but you would have noticed it before now. Typically when we see browning foliage it is either a moisture issue or potential disease. Just to rule out any disease problems you can take a sample to your horticulture Extension agent at the County Cooperative Extension Service.