GrowWrite! managing editor Michael Nolan received a warning about growing impatiens this year due to the appearance of a disease known as downy mildew (Plasmopara obducens) in South Florida and the west coast. Downy Mildew was reported in the UK in previous years including outbreaks in 2003/2004 that also impacted portions of the US.
The cover story in the January 2011 issue of GrowerTalks magazine discusses the threat and what Ball Horticultural Company and Sygenta are doing about it. GrowerTalks reports that downy mildew appeared in 2011 on the East coast, the Midwest and California.
Please be aware that this disease is specific to impatiens and only affects Impatiens walleriana and hybrids in that bloodline. Further, the disease is not seed transmitted, so plants started from seed should not be impacted.
For more information:
- USDA Agricultural Research Service
Thanks to Todd Link of Landscape Link, LLC in Decatur, GA for the tip and to Mike Minor at Saul Nurseries in Atlanta, GA for information on the story.