Garden impatiens (Impatiens walleriana) is one of the most popular bedding plants grown in American gardens.  It flowers and grows well in shade. However, downy mildew, a new disease of garden impatiens, has made it more difficult to grow and enjoy this colorful annual. 

Downy mildew was first found on garden impatiens in U.S. landscapes in the Midwest and Northeast in 2011.  To the chagrin of home gardeners and professional landscapers alike, by 2012 the disease was found on garden impatiens in all regions of Tennessee and every state east of the Mississippi River. This year the problem may be widespread.
Dr. Alan Windham, a University of Tennessee Extension plant pathologist, says that it pays to know the symptoms of downy mildew.  Early symptoms include light green, curled leaves. Later, infected plants may drop all their leaves and stop flowering.  Often, white fungal growth may be observed on the underside of leaves. 
Windham recommends that flower consumers be cautious. “When buying impatiens this year, look for healthy plants free of the fungus.  If you lost your impatiens to downy mildew last year, you might consider planting an alternative bedding plant such as begonia, coleus, New Guinea impatiens or SunPatiens,” he said. 
For more information on downy mildew and other disease and insect problems in your garden follow the UT Extension Soil, Plant and Pest Center on Facebook at:  https://www.facebook.com/SoilPlantPestCenter
UT Extension provides a gateway to the University of Tennessee as the outreach unit of the Institute of Agriculture. With an office in every Tennessee county, UT Extension delivers educational programs and research-based information to citizens throughout the state. In cooperation with Tennessee State University, UT Extension works with farmers, families, youth and communities to improve lives by addressing problems and issue at the local, state and national levels.
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Dr. Alan Windham, 615-835-4572, awindha1@utk.edu

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