Fertilizer build-up
Brown tips plus heavy feeding and a white crust on the soil usually mean salt build-up.
Diagnosis
Fertilizer build-up
What's happening
Excess fertilizer salts accumulate in the soil and burn the fine root tips, which shows up as browning leaf tips and edges and a crusty white film on the soil surface or pot rim. Dumb cane is moderately sensitive to this, and tap water high in minerals can make it worse.
How to fix it
Flush the pot: run plenty of plain water through the soil until it drains freely, several times over, to wash the salts out the bottom. Then cut back to feeding at half strength only every 3–4 weeks during the growing season, and skip feeding entirely in fall and winter. If your tap water is very hard, switch to filtered or distilled water for a while.
What fixes it
- A balanced liquid fertilizer — Switching to a gentle balanced liquid feed at half strength prevents the tip burn from coming back.
If that doesn't fix it
This is general guidance based on common symptoms; individual plants vary.
Read the full Dumb Cane care guide →
Reviewed June 2026 · how we check this