I have pots of flowers throughout my yard...many on the patio next to the side porch and some in front of the house. Some areas of the patio are shaded so I usually fill several window boxes and large pots with impatiens. I noticed however, several weeks after planting these that the plants were yellowing and dying. I pulled out all the plants, bagged them in plastic, put them in the trash and did an internet search. There is a new disease spreading through the US affecting these plants called Downy Mildew. Check the link for more information. I had not heard mention of this until it happened in my garden.
I dumped all the soil from the pots that had the affected plants behind the shop and now will have to wash the pots and window boxes with soapy water if I hope to use the same pots for impatiens next year. I did purchase the already planted pot in the picture from Home Depot in hope that the spores would not affect a new pot...so far so good.