Boston Fern: low humidity — what does it look like?

Frond tips browning and crisping, heavy shedding of dry leaflets, thinning from the outside in. Needs sustained humidity — a bathroom, a humidifier, or a pebble tray. Misting is not enough.

Boston Fern: drying out completely — what does it look like?

Whole fronds going brown and papery at once. Soil pulled away from the pot sides. Ferns have no drought tolerance at all. One serious dry-out can take the whole plant.

Boston Fern: direct sun — what does it look like?

Bleached, scorched patches on fronds nearest the glass. Forest floor plant. Direct sun burns it quickly.

Field Guide/Boston Fern

What went wrong

Boston Fern

Nephrolepis exaltata

Wants a bathroom. Sold to people with radiators.

Boston ferns die of dry air more than anything else, and they die fastest in winter when central heating drops indoor humidity to levels closer to a desert than a forest floor. Fronds crisp from the tips inward, shed everywhere, and the plant thins until there is nothing left.

The complication is that dry air and dry soil produce nearly identical symptoms, so the standard response is more watering — which leaves the roots sitting wet in air that is still far too dry.

Usually one of these

3 Likely Causes

Ranked by how often it is actually this.

01
Low humidity
The dominant cause
What you saw
Frond tips browning and crisping, heavy shedding of dry leaflets, thinning from the outside in.
What it means
Needs sustained humidity — a bathroom, a humidifier, or a pebble tray. Misting is not enough.
02
Drying out completely
Very common
What you saw
Whole fronds going brown and papery at once. Soil pulled away from the pot sides.
What it means
Ferns have no drought tolerance at all. One serious dry-out can take the whole plant.
03
Direct sun
Occasional
What you saw
Bleached, scorched patches on fronds nearest the glass.
What it means
Forest floor plant. Direct sun burns it quickly.

The question you actually have

Dead or dormant?

Part the crown and look at the very center for small tightly coiled new fronds — fiddleheads. Any pale green coil means the plant is alive and can be cut back hard and revived. If the crown is brown and dry throughout with no coils, it has gone.

If it did not make it