Spring-Summer 2012 Plant Alert: The author of this blog will not be using any Impatiens for installations during the upcoming planting season.
Following the lead of my local nursery suppliers, none of our installations this spring and summer will include Impatiens. The reason for this is Downy Mildew. (Above: University of Illinois Trial Gardens 2011, reported by Stephanie Porter, University of Illinois Extension.)
Quoting from my local supplier, Saul Nurseries, February 2012:
Downy mildew is a particularly insidious pathogen. In the landscape, it is often difficult to identify until it’s too late. Even if it is caught in time a strict and arduous spray program must be instituted to control it. Spores of downy mildew may persist in the soil for years. In the U.K., where impatiens are the top selling annual, down mildew has been devastating…. In the U.S., confirmed reports of downy mildew were sporadic but ranged from central and southern California to the Niagara region of Canada and the Midwest. Simply put, and for obvious reasons, Saul Nurseries does not want to sell plants that may be infected.
And neither do I.
Complete information can be found at the Southeastern Ornamental Horticulture Production and Integrated Pest Management site.