Just found out from my sister (who has an incredibly pale green) that she could not find the annual (in the midwest anyway) Impatiens (
walleriana) that have been damp, shady bedding plant staples in this area. A gardener friend told her that all the commercial stock was being devastated by downy mildew. I looked it up and, sure enough, there are very few commercial suppliers that are able to offer the good ole Impatiens in this area. The mildew kills the leaves and you are left will lanky, leafless stems. It is even effecting seedlings, so many of the commercial growers can't even get the plants up big enough to move out of the com-pots.
There is a link you can check for replacement plants that will grow under the same conditions, but you will have to choose another plant until they can get a grip on this mildew crap.
Alternatives to impatiens
Sorry for the bad news -
Steve