Cactus or Euphorbia? Treating Brown Tips on Succulent Stems

White, milky sap after cutting indicates Euphorbia, not a true cactus. The brown tips could stem from several causes.

Common Culprits

• Sunburn: Sudden intense light after low-light conditions.
• Watering issues: Both over- and underwatering cause tip dieback.
• Cold damage: Temperatures below 50°F (10°C).
• Fungal/bacterial infection: Often enters through wounds.

What to Do

1. Cut cleanly below the brown area into healthy tissue.
2. Let the cut callus over for a few days before watering.
3. Provide bright, indirect light; acclimate slowly to direct sun.
4. Water only when soil is completely dry.

Monitor for spreading discoloration. If it continues, suspect root rot or systemic infection—repot in fresh, well-draining mix and treat with a copper-based fungicide.