Troubleshooting worksheet
White powder on leaves
Pale, powdery patches expand across leaf surfaces, often late in the season.
Look before acting
A visual match narrows questions. It does not prove a diagnosis.
Compare the location, pattern, affected plant parts, recent weather, watering, and changes in care before choosing a response.
Possible causes
Keep the list open at first.
01Powdery mildew
02Dried spray residue
03Mineral deposits
04Other fungal growth
Questions to answer
Look at the whole plant and root zone.
- Does the material wipe away and return?
- Are crowded older leaves affected first?
- Has airflow been limited?
- Is the crop known to develop powdery mildew?
Low-risk actions
Change one thing at a time.
- Remove the worst affected leaves without stripping the plant.
- Improve spacing and airflow.
- Water at soil level.
- Use crop-specific extension recommendations if treatment is warranted.
Working checklist