yes, this is a serious problem with impatiens, and has been for a couple of years here in MA. it is a type of mildew for which there is no cure as yet (hope there will be, eventually!!).

most reputable nurseries have stopped selling them, which is good. nothing is more frustrating that seeing the plants decline and die. and they fill a niche that nothing else quite does, IMO.

new guinea impatiens do not suffer from this disease, and so far the SunPatiens brand is free of it, too.

sorry to have to share bad news, but everyone ought to refrain from buying impatiens until the problem is fixed. no point in perpetuating the disease! i believe a concerted effort is in progress to solve the situation, as impatiens are a huge money-maker.

The culprit is downy mildew.

This has happened to some of my huge impatien planters over many different years. It takes just a week or two for them to go from looking really healthy, to the stems just dropping off with all the flowers. I've asked about it and one greenhouse said to use different soil. I don't think that's it. So far, this year, they look OK. It seems to happen later on in the summer. I can't resist buying the double ones; I still have to have them! But I've gone to buying mostly geraniums---------so easy to take care of and so many colors. Mostly maintenance free!

I am so sad as I walk around the beds and where ever I had impatiens, it looks bad. Hope they find a solution. Next year I will plant the new sun impatiens and coleus which are huge this year. Wish I knew how to post pictures, would share some beauty.