Shade-brightening beds of colorful impatiens will be few and far between in the Capital Region this summer.
Downy mildew, a disease that attacks the most common variety of the popular annual, has established such a strong foothold in the region that greenhouses and garden centers are drastically reducing their stock or eliminating impatiens altogether.
For the first time, common impatiens — technically known as Impatiens walleriana — will not be available at Dehn’s Flowers and Greenhouses in Saratoga Springs.
“Last year, the area was hit really hard [by downy mildew]. I had descriptions of problems from a lot of customers,” said John Mishoe, the company’s vice president.
Dehn’s used to devote an entire greenhouse — over 3,500 square feet — to growing common impatiens.
“They’re very versatile and they’re the biggest segment of the industry,” Mishoe said.
To fill the gap, he plans to grow fungus-resistant Divine New Guinea Impatiens and a lot more begonias, which also fare well in shade.
The fungal disease ravaging common impatiens is a water mold that causes the leaves to curl and yellow. Yellow spots appear on the top side of the leaves, and later, fuzzy white spots can be found on the underside.
“The plant kind of looks like it’s water-soaked, and it will kind of wilt and die,” explained Alex Ellram, professor of plant science at SUNY Cobleskill. “It’s a disease that can really wipe out the common impatiens that we grow.”
The disease infiltrated the area during the past few years and was a major problem for growers in Long Island and western New York last year, according to Steve Ammerman, spokesman for the New York Farm Bureau.
Growers say the fungus reared its ugly head in a big way locally in 2012 as well.
“Last year, it just exploded,” said Ned Chapman, owner of Sunnyside Gardens in Saratoga Springs.
Chapman plans to cut his production of impatiens by 80 percent this year. Previously, he devoted three entire greenhouses to the popular plant. This year, only one-third of a single greenhouse will hold impatiens.
“There are customers who still want to grow them and we actually don’t know how to handle the situation,” he said.
According to Ellram, downy mildew is readily spread by wind, rain and human activity. It can also overwinter in the soil.
Once a plant is infected, there is no way to cure it.
Because of the devastating effects of the disease, Saratoga Race Course will most likely not plant impatiens this year, said Mishoe, whose business supplies the track with annuals.
Saratoga Springs, known for its plentiful planting of flowering annuals, hasn’t used impatiens in its beds for the past two years because of the downy mildew, according to the city’s public works commissioner, Anthony “Skip” Scirocco.
Faddegon’s Nursery in Latham will still have impatiens for sale this growing season, but the selection will be about 75 percent less than it was in previous years, according to Bob Graves, the company’s vice president.
“We will be putting a sign out with them that says basically, ‘If you buy these, they may die,’ ” he said. “I will bring in an initial [order], and if they don’t sell, I’m not going to get any more. Our recommendation to people is, ‘Don’t plant them.’ ”
Impatiens make up 20 to 30 percent of Faddegon’s yearly sale of annuals. Significantly downsizing the stock is going to cost the company tens of thousands of dollars, Graves projected.
Consumers looking for shade-loving substitutes will also feel the pinch, he pointed out. Common impatiens, typically sold in six-packs as seedlings, were traditionally a relatively inexpensive way to fill a flower bed. Disease-resistant New Guinea impatiens are sold as more mature plants, which cost two to three times more, Graves estimated.
Plant growers and sellers agree that there is no perfect replacement for common impatiens.
“You’re not going to have the same effect — just a carpet of flowers,” Chapman said.
Gardeners who decide to plant common impatiens despite the risk of disease should begin spraying them as soon as they are planted, with a fungicide made specifically to control water molds, said Ellram. The process will need to be repeated regularly throughout the growing season.
Downy mildew-resistant, shade-tolerant annuals such as begonias, coleus and New Guinea impatiens are less labor-intensive options, he noted.