You may have noticed that these juniper have been showing brown, dead tips this spring. Dead tips are appearing anywhere from 2 inches to 15 inches in length. The most likely culprit for this dead tissue is twig blight.
There are several twig blights that may infect juniper including pestalotia (Pestalotiopsis spp.), berckmann's (Seimatosporium berckmanssii) and kabatina blights (Kabatina juniper). Other evergreen species may play host to these fungi including the popular arborvitae. These blights usually attack trees that are already weak. Infected plant parts should be removed. Proper water and fertilization can be useful.
The most likely culprit for the blight in our area is phomopsis tip blight (Phomopsis juniperovora). Conditions that promote this fungal attack include moisture and temperatures in the 70 -- 80 degree area. While it may affect the tree from May through September it is most notable in the spring. A small, black area is usually present at the base of the dead tissue. This area may not be as visible on a dry day as it is on a wet, rainy day. Dieback may extend further down the branch as time progresses but it is usually found on young, succulent growth. If possible, prune out and destroy dead tips cutting into green tissue by at least 4 inches.
Other culprits that could be causing dead tissue in juniper are dieback and root rot. Dieback can occur after ice coats the tree for several days. It usually appears as dead tips and can easily be removed by pruning out dead tissue.
If the tree appears to be dying from the center of the tree outward and upward it may be root rot. In cases of root rot that have occurred throughout Missouri the trees may turn light green and then brown within a two week time period. When root rot is present you may also find evidence of bark beetle. There are several bark beetles that feed on Easter Red Cedar but they are usually not the reason for death of the tree. Bark beetles move in once a tree is under severe stress and already on a path to death.
Sanogo, Carmen. "Phomopsis Tip Blight on Juniper". Iowa State University Extension. Department of Plant Pathology. June 1999.
The University of Missouri Extension center is located in Kennett, Missouri at 101 South Main Street (the old bank) on the 2nd floor. Open Monday -- Friday. University of Missouri Extension programs are open to all.
Sarah Denkler is a horticulture specialist
with University of Missouri Extension
in Dunklin County.