Low humidity

Crispy, curling brown edges in dry air are the classic rex begonia humidity complaint.

Diagnosis

Low humidity

What's happening

Rex begonias are tropical understory plants that want 50% humidity or more, and their thin, textured leaves lose moisture quickly. In dry indoor air — especially near a heating vent or air conditioner — the delicate leaf margins lose water faster than the shallow roots can replace it, so the edges brown, crisp, and curl inward.

How to fix it

Raise the humidity around the plant: group it with other plants, set the pot on a tray of pebbles and water, or run a small humidifier nearby, and move it away from vents and drafts. Avoid misting the leaves directly, which invites powdery mildew on this species — ambient humidity is far safer. Trim the worst crispy edges with clean snips following the leaf's natural shape while new growth fills in.

What fixes it

  • A small room humidifier — A small humidifier near the plant keeps the edges from crisping without the mildew risk that misting brings.

If that doesn't fix it

This is general guidance based on common symptoms; individual plants vary.

Reviewed June 2026 · how we check this