Overwatering
Yellow, limp leaves while the soil feels wet; the compost smells musty and fungus gnats often fly around. Lower leaves drop and the stem base may go soft.
Roots get too little air when the soil stays wet for long, from watering too often, a pot without a drainage hole or water standing in the outer pot.
What can you do?
- Let the top 2–3 cm of compost dry out before watering again; check with your finger.
- Make sure the pot has a drainage hole and tip away water from the saucer or outer pot after fifteen minutes.
- Take the plant out of its pot and check the roots: cut off brown, mushy roots and repot in fresh, open compost.
- In the garden: improve wet, heavy soil with compost or choose plants that tolerate wet feet.
Prevention
Water according to need, not by a fixed schedule: in winter most houseplants need much less water.