Pest identification
What's eating my shimpaku juniper?
Spider mites (Oligonychus spp.)
Signs: Foliage turns dull, bronze, or rusty; fine webbing visible between scale leaves; mite dots under magnification
Control: Spray with strong water jets repeatedly; apply miticide or neem oil; ensure good airflow and avoid water stress
Juniper scale (Carulaspis juniperi)
Signs: White encrustations on foliage; yellowing and browning of scale leaves; general dieback in heavy infestations
Control: Apply horticultural oil in early spring targeting crawlers; summer treatments with insecticidal soap if infestation persists
Juniper webworm (Dichomeris marginella)
Signs: Silk-bound webbing mass on branch tips containing brown dead foliage and frass; tips die back
Control: Remove and destroy webbed masses by hand; spray Bt or spinosad on young larvae before webbing forms
Deer
Signs: Browsing of soft foliage tips in winter; can strip low branches and shape the tree unfavorably
Control: Wire mesh guards around bonsai display benches; repellent spray reapplied monthly; solid fencing for garden specimens
Keep shimpaku juniper pest-free
Healthy plants resist pests best. Get the basics right:
Shimpaku Juniper pests — FAQ
What is eating my shimpaku juniper?
Shimpaku Juniper is most seriously threatened by spider mites, which explode in hot dry summer conditions, causing bronze or rusty foliage. Juniper scale and juniper webworm also cause significant damage. In garden settings, deer occasionally browse foliage. Regular misting, good airflow, and seasonal horticultural oil applications keep most pests in check.
How do I get rid of spider mites (oligonychus spp.) on shimpaku juniper?
Foliage turns dull, bronze, or rusty; fine webbing visible between scale leaves; mite dots under magnification Spray with strong water jets repeatedly; apply miticide or neem oil; ensure good airflow and avoid water stress
How do I get rid of juniper scale (carulaspis juniperi) on shimpaku juniper?
White encrustations on foliage; yellowing and browning of scale leaves; general dieback in heavy infestations Apply horticultural oil in early spring targeting crawlers; summer treatments with insecticidal soap if infestation persists
How do I get rid of juniper webworm (dichomeris marginella) on shimpaku juniper?
Silk-bound webbing mass on branch tips containing brown dead foliage and frass; tips die back Remove and destroy webbed masses by hand; spray Bt or spinosad on young larvae before webbing forms
How do I get rid of deer on shimpaku juniper?
Browsing of soft foliage tips in winter; can strip low branches and shape the tree unfavorably Wire mesh guards around bonsai display benches; repellent spray reapplied monthly; solid fencing for garden specimens