Underwatering

What's happening

Boston ferns are not drought-tolerant — they want their soil to stay lightly and consistently moist at all times. When the mix dries out, even briefly, the fine roots can't keep the wispy fronds hydrated, so leaflet tips brown and crisp and whole fronds can go pale and limp. Dry soil that has shrunk away from the side of the pot also lets water run straight down the gap without soaking in, which makes the problem worse.

How to fix it

Water thoroughly until it drains from the bottom. If the soil has gone bone dry and water runs straight through, bottom-water instead: set the pot in a few inches of water for 20–30 minutes so the soil rewets evenly, then let it drain fully. Going forward, check the soil every few days and water once the very top feels barely dry — never let it dry out completely. In peak summer a thirsty fern may need water every day or two.

This is general guidance based on common symptoms; individual plants vary.