I am not sure whether this problem has been specifically addressed on the forum. I have had great success with impatiens in my shade garden, until about a month ago. Something has been neatly eating the leaves off of the plants, leaving the naked stalks and flowers. The problem started centrally in my garden, and has spread outward in almost a circle. The plants at the periphery are the least affected. I haven't seen a specific insect. Anyone else have this problem? What could be causing it? I'm assuming that it is some type of insect. Thank you!