Why Does My Calathea Have Crispy Brown Edges? (And How to Stop It)

First, take heart: you have not failed her. Calatheas are the theater kids of the houseplant world, and crispy brown edges are their signature performance. The most likely cause is your tap water. Calatheas are unusually sensitive to the fluoride, chlorine, and dissolved minerals in most tap water, and those salts collect in the leaf tips and edges until the tissue burns. Dry indoor air, especially near heaters and vents, finishes the job. Daily misting, sweetly intended, usually raises humidity for only a few minutes.

What to do

1. Switch to filtered, distilled, or rainwater. This is the single biggest lever.
2. Raise humidity for real: group plants together and park a small humidifier nearby. A pebble tray is harmless but does little for the air around the leaves.
3. Keep the soil evenly moist but never soggy, and do not let it dry out completely between waterings.
4. Move her away from vents, radiators, and drafty windows.
5. Trim the crispy edges with clean scissors, following the leaf's natural curve. This is purely cosmetic, and that is fine.

What to expect

Damaged edges never turn green again, so judge your progress by new leaves only. If the next leaf that unfurls over the coming four to eight weeks comes in clean, you have won. She will still be dramatic. That is simply who she is.