Too little light
A fern that goes pale, thin, and sparse in a dim corner simply isn't getting enough light.
Diagnosis
Too little light
What's happening
Boston ferns like shade, but they still need bright, indirect light to fuel full, healthy growth. In a genuinely dim spot the plant can't power dense fronds, so new growth comes in pale, weak, and widely spaced, the plant thins out, and older fronds yellow and drop faster than they're replaced. It's the opposite of sunburn but shows up in a similar washed-out color.
How to fix it
Move the fern to a brighter location with plenty of bright, indirect light — near an east or north window, or a few feet back from a curtain-filtered brighter window. Avoid jumping straight into direct sun, which it can't handle. If your space is genuinely dark, a full-spectrum grow light run for a stretch each day makes a real difference and is often the only way to get full, green growth back.
What fixes it
- A full-spectrum LED grow light — A full-spectrum grow light gives a fern in a dim room the bright indirect light it needs to stay full and green.
If that doesn't fix it
This is general guidance based on common symptoms; individual plants vary.
Read the full Boston Fern care guide →
Reviewed June 2026 · how we check this