Why Are My Houseplant Leaves Turning Yellow?

Overwatering is the most common cause, especially when yellowing starts low on the plant and the soil stays wet for days. Let the pot dry appropriately and make sure drainage holes are open.

One old yellow leaf can be normal. Many yellow leaves at once, soft stems, black spots, or a sour soil smell point to a larger care issue.

A plant moved into deep shade may shed leaves. Sticky residue, webbing, or tiny specks on leaf undersides can indicate pests that need isolation and treatment.