Multiple Plant Damage in Cold Damp Weather: Diagnosis

Bird of Paradise, Persian Shield, Pentas, Ruellia, Jasmine: Winter Decline

Multiple species showing brown leaves, holes, white stem bumps, scale-like foliage, plus a strange "wormy thing" (fat head, eyes, fangs, 1") after cold, damp winter: primary cause = cold/damp stress; secondary = pests exploiting weakness.

Cold/Damp Primary Damage

• Tropical/subtropical plants in marginal zone suffer chilling injury
• Cellular damage → necrotic spots, leaf drop, poor vigor
• Wet soil + cold = root dysfunction → symptoms mimic drought

Pest Opportunists

• White bumps on stems: Likely scale insects (immobile adults)
• Holes in leaves: Slugs/snails (night), caterpillars, or beetles
• Scale-like foliage: Could be spider mite stippling or fungal spores
• Mystery larva: Possibly white grub (beetle larva) or caterpillar—hard to ID without photo

Action Plan

1. Prune dead/damaged tissue—improves air flow, removes pest habitat
2. Horticultural oil for scale (late afternoon, rinse next AM)
3. Iron phosphate bait for slugs/snails
4. Bt (Bacillus thuringiensis) for caterpillars
5. Wait for warmth—most recovery happens when nights >55°F

Don't Over-Treat

Cold-stressed plants are chemically sensitive. Minimal intervention + warming weather = best recovery.