Janet, The sad news is there is nothing in the market for home gardeners. And if they find something it will not be a silver bullet. Homeowners will be required to spray their plants every two weeks to keep Impatiens Downy Mildew (IDM) from attacking the plants. Recommendations for replacements include begonias, coleus, caladiums. I will be writing more about it in the coming months. Best And Happy Yardening, Nancy.
Suggested Replacements For Impatiens
Question From: J. Turner - MICHIGAN
Q: What are you suggesting to replace Impatiens in our gardens? Or, have they solved the disease problems of last year?