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Thursday - April 08, 2010

From: San Antonio, TX
Region: Southwest
Topic: Trees
Title: Ashe Juniper not doing well in San Antonio
Answered by: Barbara Medford

QUESTION:

A large ash juniper (mountain cedar) in my yard appears to be sick or dying. Approximately 1/4 of the canopy has very sparse needles/green foliage stuff and shaggier than normal bark. It's not brown or rusty in appearance, just very sparse compared to the rest of the tree. Since its so tall, I can't inspect the branches up close to look for signs of infestation, but in researching known pests, I read that cedars really aren't prone to any disease. How can I determine if my tree is sick or dying? Any ideas? Is there anything I can do to help it?

ANSWER:

We agree, you don't ordinarily think of this plant as having problems. More people want to get rid of it than take care of it. Because we are not plant pathologists and, of course, can't see the tree in question, we went hunting on the Internet to see if we could find clues for you. Some of these have pictures, and we will give you a link to a couple of Google Images sites to compare with your tree. The two from New Mexico State University and West Virginia State University were the only mentions of spider mites. One was written two years ago and mentions that the weather had been dry, which helped contribute to spider mite infestation. We have an opposite situation here this year, with a lot of rain.

If you get the impression that we really don't know what is causing the die-back on your tree, you are absolutely right. After you have read these sites, and compared the symptoms with your tree, we suggest you contact the Texas A&M AgriLife Extension Office for Bexar County. They are more likely to be familiar with this problem than we are.

Cornell University Juniper Tip Blight "Drought, freezing, dog urine and transplant shock can cause similar dieback symptoms."

Morton Arboretum Juniper Tip Blight "Common disease of junpers in most states east of the Mississippi River."

West Virginia University Extension Service Twig Blight of Juniper "This disease could be confused with cold injury or spider mites." Images of Juniper Twig Blight from Google.

USDA Forest Insects & Disease Leaflet Phomopsis Blight of Junipers

New Mexico State University Juniper branches turning brown Blames spider mites.