Canaerti juniper disease - Ask Extension
Will my 4 canaerti junipers recover from this needle browning/drop in future years or should I replace them this fall? I understand the presence of an...
Knowledgebase
Canaerti juniper disease #351137
Asked August 08, 2016, 9:29 AM EDT
Will my 4 canaerti junipers recover from this needle browning/drop in future years or should I replace them this fall? I understand the presence of an ornamental crab apple tree nearby may be contributing to this problem. If so, would my trees recover if i get rid of the crab apple?
Jefferson County Kentucky
Expert Response
Cedar Apple (or hawthorn) rust is most destructive to apples, crab apples and hawthorns than to the juniper or eastern red cedar (actually a juniper) in our landscapes. The disease causes a gall to form on the juniper, not needle loss as in the photo. Information on this disease is here:
https://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-FR-T-05.pdf
Plant recovery will depend on what is actually causing the browning of needles. pruning out the dead branches may improve the look of the junipers. Brown needles will not green back up so the affected tissue is dead.
The photo shows the browning of needles from the inside of the branch outward.
Both disease and environmental conditions could cause this. Bring in a branch that has both brown and green needles so that we can see the progression of what is occurring. If we can not identify the problem here then the sample can be sent on to the lab at UK. The two most destructive twig blights of juniper usually start at the tips of the branches.
Twig blight of junipers:http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/ppfshtml/ppfs-or-w-11.pdf
https://www2.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-FR-T-05.pdf
Plant recovery will depend on what is actually causing the browning of needles. pruning out the dead branches may improve the look of the junipers. Brown needles will not green back up so the affected tissue is dead.
The photo shows the browning of needles from the inside of the branch outward.
Both disease and environmental conditions could cause this. Bring in a branch that has both brown and green needles so that we can see the progression of what is occurring. If we can not identify the problem here then the sample can be sent on to the lab at UK. The two most destructive twig blights of juniper usually start at the tips of the branches.
Twig blight of junipers:http://www2.ca.uky.edu/agcollege/plantpathology/ext_files/ppfshtml/ppfs-or-w-11.pdf
Feel free to contact our office if you have other questions.
Let me know if I can help you further!
Carol Wilder
Horticulture Technician
Jefferson County Cooperative Extension Service
<personal data hidden>
810 Barret Ave
Louisville KY 40204
