Permanent Scars on Cactus: Spine Damage vs. Scale Insects

Dry brown sores on small cactus from larger plant's spines or scale insects: both cause permanent scarring. Cactus skin doesn't regenerate.

Scar Types

Diagnosis

1. Magnify (10x): bumps = insects; flat scars = physical
2. Scrape: waxy = scale; hard = cork
3. Check neighbors: same spots = pests

Treatment

• Physical scars: None needed; cosmetic only
• Scale/mealybugs: Alcohol swabs → horticultural oil → systemic
• Fungal: Copper fungicide; improve airflow

Prevention

• Space plants (no spine contact)
• Inspect weekly with magnifier
• Quarantine new plants
• Airflow + dry culture

Cactus Mall Pest Guide for detailed ID. Scars are permanent but don't harm health if not pathogenic.