darker leaf impatiens are getting silvery hue
My darker leaf impatiens are getting a whitish silvery hue to the top of their leaves. Additionally, the leaves, over time, have begun to turn from their original dark green color to a brownish/red hue. The are also dropping leaves, leaving tall stalks with a few leaves and flowers on them. Most of these plants are in the full sun, under a screened patio. They are in clay pots and are watered daily. They were all planted 4-5 months ago and have had time to acclimate to the sun. The screening does not offer shade, but does filter the sunlight (for people, anyway.) If this environment is not good for these plants, could you suggest other colorful flowering plants that might do better here? Thanks for your help.
Your impatiens are possibly afflicted with gray mold (botrytis), which thrives in humid, damp conditions. My other thought was downy mildew, but that usually presents itself on the underside of the leaves, not the top. The article below outlines a plan of care to help deter the mold from growing - be ready to get out your pruning shears with an approved fungicide in hand.