Happy plants start with a little care.

Check whether the soil stays wet for days, whether the pot drains, and whether the plant gets suitable light. An occasional older leaf can yellow naturally.

Check the soil before adding water. Dry soil may need a thorough watering. If the mix is already wet, check drainage and let the plant recover in suitable light.

Look closely at both sides of the leaf. Cottony clumps, powdery growth, and dried water marks have different causes. Separate the plant if you suspect pests or disease.