Lack of impatiens a blow to gardeners
PHILADELPHIA — For decades, it's been a rite of spring.
You hop in the car, head for the nearest garden center and load up on impatiens, the best-selling, candy-colored annuals that thrive in shade, mound up like half a beach ball, and bloom their heads off till frost, asking little in return.
But this year, disaster looms.
There will be far fewer impatiens for sale. Gardeners who buy them will be taking a risk that experts say isn't worth it. The plants will probably die, and the shade-loving alternatives being offered up may not cut it for many who depend on the easygoing, affordable impatiens to brighten their summer landscape.
The culprit in this gloomy scenario is well-known in the trade and virtually unknown to consumers: downy mildew, a deadly, funguslike disease that targets the popular garden plant known as Impatiens walleriana.
In 2011, the disease was confirmed in 11 states. In 2012, it was in 34, including Pennsylvania and New Jersey. The damage this year is anybody's guess, but there's no question there will be damage.
“The feeling is, it's really going to be pretty much everywhere,” says James Harbage, research and production leader at Longwood Gardens in Kennett Square.
The news is devastating for gardeners like Myrna Pope.
Over the last 30 years, she has planted thousands of impatiens on her shady 1.5-acre property bordering the Wissahickon in Chestnut Hill. Living without them is unthinkable.
“I'd be hysterical!” she says.
Once the plant is infected by the mildew spores — found in soil, water and winds from as far away as a hundred miles — small yellow spots appear on the tops of the leaves and fluffy white-gray growths on the undersides.
There's no cure, and no affordable, foolproof way to forestall the end. The plant shrivels and dies in a matter of days or weeks, while the offending spores can live on in the soil for a year or two or more.
Cool temperatures, high humidity, and moisture from rain and overhead sprinklers or irrigation systems fuel the spread of the disease. And spores in the ground can survive the winter.
“They've figured it out. During dormancy, they form a very thick-walled spore that's resistant to cold and flooding and drought,” says Gary W. Moorman, Pennsylvania State University plant pathologist. He believes that the downy mildew problem could cripple impatiens production and sales for years.