Overwatering
Wet soil plus yellowing lower leaves points squarely at overwatering — the fastest way to lose a dumb cane.
Diagnosis
Overwatering
What's happening
Dieffenbachia has thick, juicy stems and roots that need air as much as water. When the mix stays soggy the roots can't breathe, so they begin to suffocate and rot, and the plant sheds its oldest lower leaves first — they turn a soft, uniform yellow and droop before they drop.
How to fix it
Stop watering and let the soil dry well down. Slip the plant out and check the roots — firm and pale is healthy, so trim any brown, mushy roots with clean scissors and repot into fresh, airy, well-draining mix in a pot with drainage holes. Going forward, water only when the top 1–2 inches feel dry, and always empty the saucer so the pot never stands in runoff.
What fixes it
- A soil moisture meter — A moisture meter removes the guesswork — only water when it reads dry an inch or two down.
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