Low humidity damage
Browning, curling and crisping of leaf edges and tips on tropical plants kept in dry air, often indoors in winter.
Also known as: Dry air injury, Crispy leaf edges
Symptoms and identification
Leaf edges and tips turn brown and crisp, leaves curl inward or look dull, and new leaves may open small or fail to unfurl. Calatheas and prayer plants fold their leaves, and buds on flowering plants may dry out before opening.
Causes
Heating, air conditioning, and bright, sunny windows dry the air to levels far below what tropical plants need, which is often 50 per cent or more. Plants placed near radiators or vents are most affected.
Organic treatment
Move plants out of dry air, raise humidity, water evenly and trim off brown tips with clean scissors. Misting gives only a very brief lift in humidity.
Prevention
Group plants together, use a humidifier or a pebble tray of water, and keep plants away from heaters, vents and draughts. Choose tougher plants for dry rooms, or grow humidity-lovers in a bathroom.
Chemical treatment (use with care)
No chemical treatment is needed. Fix the air humidity and the browning stops spreading.