NYSTA
Calendar of
Events
Southeast
Regional
Conference
January 22-23,
2013
Ramada Inn, Fishkill,
NY
Western Regional
Conference
February 25, 2013
Millennium Hotel,
Buffalo, NY
Adirondack
Regional
Conference
March 20, 2013
High Peaks Resort,
Lake Placid, NY
14th Annual
Sullivan County
Challenge – Steve
Smith Memorial
Golf Tournament
A Change for Landscape Beds
Brian Eshenaur, New York State Integrated Pest Management Program
It will be different in 2013. We will be seeing less of one of the most popular
bedding plants used in landscapes—garden impatiens. In fact some New
York greenhouse growers who produced thousands of flats in past years will
not be growing any this spring. It’s all due to a new disease of impatiens
called downy mildew. This devastating water mold (related to late blight of
potatoes and tomatoes) became widespread through much of the country
over the last two years.
When it shows up it can cause a beautiful flowering mound of impatiens to be
a bare stand of stems in a week’s time. One of the challenges with this
disease is that it’s airborne and even if the impatiens plants that a landscaper
installs in a client’s property are completely healthy when they are planted,
the disease can move in from wind blown spores and in a short time ruin the
planting. This happened at some locations in NY late in the summers of 2011
and 2012. Most of the landscapers that had plantings affected by this disease
are planning to use alternative plants this year. This could be a hard sell for
some commercial and residential clients because there are no perfect
substitutes that tolerate the shade so well and bloom from spring planting to
the first frost. But there are some plants to try and breeders are actively
working on new varieties of garden impatiens that will have resistance.
More About Impatiens Downy Mildew
 Plasmopara obducens is the name of the water mold responsible for
this disease. It can spread quickly with wet weather. Overhead
irrigation will increase the risk of infection.

Not only is the disease airborne it can also survive overwinter in the
soil through spores in infected plant debris. When impatiens are
planted into infested soil the disease is likely to appear sooner in the
growing season.

It is not practical to treat infected landscape plantings with fungicides.

All varieties of garden impatiens (Impatiens walleriana) are
susceptible but other New Guinea impatiens (Impatiens hawkerii )
and other bedding plants are not susceptible.
August 21, 2013
Grossinger Resort,
Liberty, NY
Hahn Memorial
Scholarship Golf
Tournament
October 7, 2013
Turf & Grounds
Exposition
November 12-14,
2013
Rochester Riverside
Convention Center,
Rochester, NY

Some plants that landscapers may consider as a substitute for garden
impatiens:
o
o
o
o
o
o
o
o
Annual Vinca
Begonia (both wax and the new angel wing varieties)
Browellia
Coleus
Lobelia
New Guinea impatiens
Sunpatiens
Torenia
New guinea impatiens are one of the alternative that are resistant to downy mildew.
Landscape impatiens defoliated due to downy mildew in 2013.
Sponsored by Grassland Equipment and Irrigation Corp., Inc.
www.grasslandcorp.com
www.turfequipmenttrader.com