Boston Fern: Complete Care Guide

The Boston fern (Nephrolepis exaltata) is the most popular indoor fern, and for good reason: its green, arching, feathery fronds bring a jungle freshness to any corner. It has a reputation for being fussy, but it all comes down to one word: humidity.

Why humidity is everything

In the wild it lives in damp, shady forests. Indoors, dry air — especially with heating on — is its greatest enemy and the number-one cause of brown fronds. Master humidity and you master the fern.

Humidity: the key

It needs high ambient humidity, above 50-60%. To achieve it:

Place it in a bathroom or kitchen with good light.
Group it with other plants.
Use a humidifier (the most effective option).
Set it on a tray of pebbles and water, with the pot above the water line.

Misting helps only briefly and momentarily; it's no substitute for genuine humidity. To dig deeper, read our guide to humidity for plants.

Watering

The soil should stay slightly moist at all times — never soggy and never bone dry.

Water when the surface starts to dry, usually 2-3 times a week in summer.
In winter, water less often but don't let the root ball dry out completely.
If the soil dries fully, the fronds quickly turn brown.

Light

Ideal: bright to medium indirect light.
Tolerates: some shade.
Avoid: direct sun, which scorches and dries the fronds instantly.

Temperature

It prefers mild temperatures, between 60 and 75 °F. Keep it away from radiators, heaters and hot or cold drafts, which dry out the air around it.

Soil and repotting

Use a mix that holds moisture but drains excess: all-purpose soil with coco coir and a little perlite. Repot in spring when roots fill the pot, into one only slightly larger.

Upkeep

Trim brown or dry fronds at the base to encourage fresh growth.
Feed every 4 weeks in spring and summer with diluted liquid fertilizer.
Every few years you can divide the plant to propagate it.

Common problems

Brown, crispy fronds: air too dry or not enough water. The most common issue by far.
Pale, yellow fronds: too much light or a lack of nutrients.
Massive leaflet drop: heat shock or extremely dry air.

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