Ring spot from water temperature
A temperature difference between water and the leaf can cause pale rings or blotches. Splash history supports this explanation, but the shape of a mark alone does not rule out other damage or disease.
Use room-temperature water and keep it off the crown and foliage where practical. Water the mix carefully from above or use bottom watering, then drain. Existing injured tissue will not recover; keep useful leaves unless badly damaged. Continuing spread after changing watering needs a fresh check.
Sun exposure and splashes
Strong sun and temperature changes can injure leaves. Do not assume every brown spot after watering is caused by droplets acting as tiny magnifying glasses; appearance alone cannot establish that mechanism.
Keep the plant in filtered light and gently blot accidental splashes without rubbing the hairy surface. Investigate enlarging lesions, soft tissue or new damage on unsplashed leaves.
Mineral residue (not actual leaf damage)
A deposit sits on the leaf surface; a damaged patch is part of the tissue. Avoid scraping or forceful wiping. A persistent white coating could have another cause, including powdery mildew, rather than simply water residue.
Take photographs and seek identification if the coating returns, spreads or accompanies deteriorating growth. Do not treat an unidentified problem with a fungicide merely because it looks powdery.
Keep a short care record
Photograph the whole plant and any damage, and note moisture checks and recent changes. Compare later growth rather than expecting an old scar to disappear. Continuing collapse, expanding lesions or extensive decay deserves specialist help.
Reference material
Reference material consulted for this independently written guide. The publishers listed have not reviewed or endorsed it.
- RHS — African violets
- University of Maryland — watering
- University of Maryland — symptom checks
- University of Minnesota — African violets
- Pacific Northwest Plant Disease Handbook — ring spot