Downy Mildew On Impatiens - Pictures Too

What was once my stellar performer around here may become history, at least until next year...maybe. Symptoms are identical to my mother's Impatiens that suffered earlier this year in SW Florida. Both she and I assumed it was a heavy overnight deluge. Same up here in North Georgia. There was a heavy rain in the middle of the night on May 30 with another inch and a half falling on or around June 4.



This is not the case and the problem has almost been confirmed in an email by Dr. Jean Williams-Woodward with the University of Georgia who states it "looks like downy mildew." Some of the resources available:

http://blog.caes.uga.edu/sehp/2012/02/11/new-downy-mildew-affecting-impatiens/

http://blog.caes.uga.edu/sehp/2012/06/15/downy-mildew-on-impatiens-identified-in-georgia-retail-nursery-and-landscape/

Where did this nasty disease come from? What can be done? How rampant will it become? Here's a story from the UK. In short it only appears during wet and cooler weather, which we did have the last two weeks. It may slow down or halt when the weather gets hot. Pretty depressing when you consider Impatiens represents a large potion of my gardens. Surprisingly some areas are still flourishing, while others look done. Can I blame it on the source? Possibly, but not enough is known. Some were purchased at Lowes in mid April while others from Quinn's Greenhouse up McCaysville, Georgia. Problem is some were mixed in with others. I would have more faith in buying disease free stuff from Quinns over Lowes. Are they capable of preventing it? It's almost an unknown at the present time. Plenty of facts and opinion at the links above.

More pictures..

And one area not affected (below)...yet. Wait. There is one white Impatiens in the image that has definitely not progressed as well as the others shown. Maybe there's a way of detecting if your Impatiens have the disease but it hasn't yet shown it's ugly face? For weeks I've been thinking none of my Impatiens are progressing as well as they did in past years. Yet during that time there were no signs of any disease. They just remained smaller. But then again I can be impatient, thinking how everything looked in mid July of previous years.

What about Impatiens that reseed?  I do have several areas that are being affected, but they too are mixed in with newer plants this year. Oh well, at least my trailing Petunias are thriving.