Members of the African violet family are very sensitive to rapid temperature changes. Water spots occur most commonly when cold water is splashed on the leaves while the plant is being watered. If this happens in light, the chlorophyll (green pigment) is destroyed. In this plant family, all of the chlorophyll in the leaves is found in a single layer of cells near the upper surface. If the chlorophyll in that layer is broken down, the green color disappears, and the color of the underlying leaf tissue is exposed.
Avoid getting cold water on African violet leaves when watering. Or use water at room temperature, which will not cause spotting if it touches the leaves. Spotted leaves will not recover. Pick them off if they are unsightly.
Plant Care for Saintpaulia