Chlorosis.
A loss or reduction of normal green coloration, commonly seen as yellowing tissue.
What it means for your plants
Chlorosis describes appearance, not a single diagnosis. Nutrient availability, damaged roots, unsuitable moisture, or other stresses can be involved. Inspect the whole plant and recent care before treating.
IN PRACTICE
Several yellow leaves in a persistently wet pot warrant a root and drainage check before adding fertilizer.
Put it into practice
Work through yellow leaves using leaf age, moisture, light, pests, and recent changes before choosing a treatment.
Why are my houseplant leaves turning yellow?