7 Signs of Overwatering — and How to Save an Overwatered Plant
Overwatering, not underwatering, is the most common way houseplants die. Seven signs to look for, and what to do step by step when you spot them.
When a plant wilts, most people reach for the watering can. Yet the most common cause of houseplant death is too much water. Roots that sit wet can't breathe, start to rot and stop taking up water — which is why an overwatered plant wilts as if it were thirsty.
7 signs of overwatering
- Leaves droop even though the soil is wet — the symptom most often mistaken for thirst.
- Lower leaves turn yellow and fall off easily.
- The base of the stem turns soft or black.
- The soil smells sour or musty.
- White mould or moss grows on the soil surface.
- Tiny flies (fungus gnats) hover around the pot.
- Leaves develop blisters or brown spots.
How to tell it from underwatering
Push a finger 2 to 3 cm into the soil. Wet soil with drooping leaves means overwatering; bone-dry soil with crispy leaves means underwatering. A wooden chopstick pushed into the pot works too — see if damp soil clings to it. Best of all, learn how heavy the pot feels right after watering and when it's dry.
How to save an overwatered plant
- Stop watering and empty the saucer.
- Move the plant somewhere bright and airy, out of direct sun, so the soil dries.
- If it hasn't improved in one to two weeks, or the stem base is soft, slide the plant out and check the roots.
- Healthy roots are white or light tan and firm. Cut away black, mushy, smelly roots with clean scissors.
- Repot in fresh, dry mix in a pot with drainage holes and give a light watering a few days later.
A pot that's too big for the plant holds water for too long. When repotting, go up only 2 to 3 cm in diameter.
Habits that prevent overwatering
- Water when the soil is dry, not on a fixed weekly schedule.
- Avoid pots without drainage holes, or use a plastic nursery pot inside them.
- Water less often in autumn and winter.
- When you do water, water until it drains from the bottom, then wait until the soil dries again.
Plants that store water in their leaves — snake plants, ZZ plants and succulents — are especially prone to overwatering. Check each plant's watering interval in the GreenPic encyclopedia, and add it to My Plants to get a reminder when it's due.