Wind-carried disease threatens impatiens, a favorite CNY garden plant

Healthy impatiens

Mounds of bright-colored impatiens are part of many shade-area gardens, but this year thereâ??s a warning about planting the popular bedding plants.

Thereâ??s no official ban on selling impatiens and you can find them for sale in flats and in hanging baskets at large retailers, some garden stores, and at farmersâ?? markets.

But in January, Cornell Cooperative Extensions began putting out warnings to growers, suggesting they not market the popular plants this year.

The culprit is downy mildew, a wind-blown spore. Plants can be healthy at sale but if they are attacked, the leaves can fall off within a week leaving the bare stems.

Some greenhouses have put up warnings.

"Weâ??re trying to keep this contained. New York is the worst state," says Carol Watson, whose Carol Watson Greenhouse in LaFayette has a big advisory banner and offers alternative plants.

Itâ??s specifically the SEED impatiens that can be blighted, but New Guinea impatiens is immune. Itâ??s usually sold as a big hanging basket plant, but itâ??s already been hybridized to a smaller bedding plant.

Begonias, in many varieties, are also safe choices and there are other colorful shade plants available, says Watson.

While there is no restriction on selling, New York Stateâ??s Agriculture and Markets inspectors are checking for-sale plants more closely and say theyâ??ll quarantine and destroy any diseased plants they find.

The problem is, impatiens may look healthy at sale and get attacked later.

Thereâ??s another reason for this yearâ??s concern. Itâ??s believed the downy mildew spores can overwinter in soil, meaning if they have lots of targets and can multiply this year. That means the problem wonâ??t go away soon.

"If we can contain it and respect the fact of not to buy them and not to grow them, then in 2014 the seed is going to be clean again," says Watson.