What's eating my incense cedar?

Incense Cedar (Calocedrus decurrens) is most seriously damaged by incense cedar bark beetles, which attack stressed or drought-weakened trees. Cedar quince rust causes orange galls on branch tips. Aphid colonies and scale insects can build up on foliage. Deer occasionally browse young trees but largely leave mature specimens alone.

Pitch tubes and frass on bark; S-shaped larval galleries under bark; crown dieback beginning in upper canopy. Prevent drought stress with supplemental watering during dry summers. Remove and chip infested wood. Preventive carbaryl or pyrethroid bark sprays for high-value trees before spring beetle flight.

Large dark colonies on twigs; honeydew drip causing sooty mould below; minor foliage yellowing. Insecticidal soap or neem oil spray onto colonies. Encourage predatory insects. High-pressure water jet for accessible infestations.

Circular reddish-brown scales clustered on bark of smaller branches; twig dieback and slow decline. Dormant horticultural oil in late winter. Prune out heavily encrusted branches. Systemic imidacloprid drench for persistent cases.