Norfolk Island Pine Black Spot: Prune, Fungicide, Fertilize

Diagnosis

Drying needles + black spots on affected branches = pine needle blight or brown spot fungus (Mycosphaerella spp.). Common on indoor Norfolk pines in low light, high humidity.

Treatment Plan

1. Prune dead branches: Cut to healthy wood (green cambium). Disinfect pruners between cuts.
2. Fungicide: Ortho Multi-Purpose Fungicide (chlorothalonil) or copper spray. Apply per label; repeat 7–10 days.
3. Fertilize: Balanced 10-10-10 at half strength monthly during growth.
4. Environment: Bright indirect light, rotate weekly. Humidity 50%+. No drafts.

Prognosis

Rarely kills the whole plant. Lower branches naturally shed over time. Focus on maintaining upper canopy health.

Certified arborist can treat large specimens, but $150–200. DIY with $20 fungicide works for most houseplants.