pests and diseases
Chlorosis
Last reviewed 2026-10-04
Chlorosis is the loss of green color from plant tissue because chlorophyll is reduced. Leaves may become pale green or yellow, but the pattern and age of affected leaves matter. Chlorosis can result from nutrient deficiency, unsuitable pH, damaged roots, disease, light, temperature, or water stress.
What it means
Chlorosis is a symptom, not a diagnosis. Uniform yellowing of older leaves can have a different cause from yellow tissue between green veins on young leaves. Similar patterns can also result from root damage that prevents nutrient uptake even when the soil contains the nutrient.
How it affects the garden
Do not apply fertilizer solely because a leaf is yellow. Check watering, drainage, light, root health, recent weather, and the plant's normal color. A reliable soil test can reveal pH and nutrient conditions. Correct the cause rather than treating the symptom with repeated applications.
The soil pH amendment calculator helps estimate an amendment after suitable inputs are known. The can I grow this tool helps review basic site fit but does not diagnose disease.
Example
Young leaves show green veins with yellow tissue between them. That pattern may suggest an iron-related availability problem, but pH, root condition, and the crop are needed before selecting a response.
Common confusion
Chlorosis is not the same as natural autumn color or a dead leaf. It also is not proof of nitrogen deficiency.
Sources
University of Minnesota Extension explains chlorosis patterns and why soil conditions affect nutrient availability.
