Junipers Turning Brown and Dying

Phomopsis Tip Blight

• A juniper is susceptible to several twig and tip blights caused by different fungi that result in junipers turning brown and dying. Phomopsis tip blight is caused by the fungus Phomopsis juniperovora and primarily affects new growth of tips and shoots. Twigs initially turn pale, then reddish-brown before turning completely brown upon dying. The disease comes to life in the spring during warm, wet conditions. Dark cankers form at the juncture of live and dead wood.

Kabatina & Cercospora Blight

• Kabatina twig blight is a result of infection by the fungus Kabatina juniperi. It produces the same damage to a juniper as does Phomopsis tip blight, aside from the fact that it attacks primarily middle-aged twigs.

  Cercospora twig blight is caused by the fungus Cercospora sequoiae var. juniperi and completes the cycle of injury by focusing its damage on the most mature twigs. It slips onto old needles situated on low branches near the interior of the bush. The browning and dying of needles spreads upward and outward.

Blight Management

• All three twig blight diseases should be managed in the same manner. Maintaining the health of a juniper is the ideal preventive treatment. The bush should not be planted in a shaded area or a location where the soil is excessively moist, as these conditions are ideal spawning grounds for juniper twig blights. Immediate pruning of diseased and browning branches usually is sufficient to control the damage.

Juniper Webworm

• The Juniper webworm (Daeborneris marginella) is the larval form of an adult moth that makes its home amid the foliage of a juniper. Upon hatching, the juniper webworm feeds on the needles of the bush, protecting themselves with silken structures they spin over the feeding site. The feasting causes the foliage to turn brown, and the webworm overwinters on the plant, ready to cause similar damage in the spring. Chemical control helps to manage the pest.