Cotoneaster Hedge: Spider Mites and Powdery Mildew, Not Spiders

Cotoneaster hedge with dead sections, powdery mildew, and spider webbing—spiders are predators hunting real pests (mites/aphids). Sevin ineffective and harmful.

Real Problems

• Spider mites: Cause bronzing, webbing, death—check leaf undersides
• Powdery mildew: White powdery coating, favored by shade/humidity
• Spiders: Beneficial—eat mites/aphids. Webbing = hunting platform

Diagnostic Step

Snip affected twig with mildew → local nursery for ID and targeted recommendation.

Management

• Mites: Horticultural oil, insecticidal soap, or miticide (not Sevin)
• Mildew: Chlorothalonil, propiconazole, or sulfur
• Cultural: Thin for air flow, avoid overhead water, full sun

Accurate ID essential. Spiders are allies—don't kill them.