Impatiens and downy mildew*

(Question)

Will they be available to purchase in 2016? Has the disease been taken care of?
Thank You

(Answer)

While you may find some bedding impatiens available in the nurseries this spring the disease has not gone away. Margery Daughtrey from the School of Integrative Plant Science at Cornell University suggests that we are hearing less about the disease as growers have shied away from producing plants that will not perform reliably. With fewer host plants available, there are fewer instances of the disease.

It appears that the spores from downy mildew can overwinter and infect new plants the following year. Particularly, if you have had impatiens downy mildew in your garden, you’ll want to continue to stay away from bedding impatiens. It is not yet known how long the spores can survive in the soil.

Impatiens downy mildew only affects the bedding impatiens (Impatiens walleriana).   Other types of impatiens including New Guinea impatiens and the Sunpatiens series continue to be available and can be safely grown. Research is focusing on breeding new hybrid impatiens that are less susceptible to the disease. A hybrid impatiens called Bounce and Big Bounce are coming increasingly available.

There are other good bedding plants such as begonias, coleus and torenia that thrive under similar shady conditions. A fact sheet on Alternatives to Garden Impatiens has been prepared by Cornell Cooperative Extension.