For the last couple years, I have been reading ominous reports of downy mildew decimating impatiens plants. As most of you know, it’s more than just reports now. It’s real—to the extent that entire plantings of traditional impatiens (impatiens walleriana) have been completely wiped out throughout the United Kingdom, and parts of the U.S. The mildew, caused by the pathogen Plasmopara obducens, kills the plants; if caught in time, they can be treated, but once the spores have taken hold, they’re pretty much unstoppable. There’s a good description of the disease, its symptoms, and its treatments here.
One of the articles I saw mentioned the presence of this in impatiens beds as close as Niagara Falls, Ontario, only about 20 minutes or so away from me.
A Philadelphia Inquirer report said this about anyone who is thinking about using impatiens this year:
Gardeners who do 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 feeling is, it’s really going to be pretty much everywhere,” says James Harbage, research and production leader at Longwood Gardens in Kennett Square.
And here are some observations from Newsday:
“The best and really only way to avoid a reoccurrence is to plant something else,” said Cornell University plant pathologist Meg McGrath, who is based in Riverhead and has been tracking the disease’s progression. The pathogen can be transmitted from infected seeds, on leaves or via airborne spores, and planting impatiens next year – even in another location – will just feed the hungry beast.
I can almost feel the vibrations from your collective shrugs, and can imagine the universal so whats. Who cares about impatiens anyway, right? And besides, the New Guinea varieties and the Sunpatiens aren’t affected by the disease, supposedly.
This is fine for landscapers, who want the ease of impatiens in a sunny spot, but it doesn’t help shade gardeners who actually like impatiens, within reason. I am one of those gardeners. The old-fashioned impatiens really spread well, in my root-filled, shady front garden. I like them for my one floral accent amid all my shade-friendly foliage plants. The semi-doubles (as opposed to the unreliable full doubles) are lovely, and the new Fusion (a walleriana hybrid) achieves shrub-like stature. I hate New Guineas, and if I had sun, I wouldn’t be planting impatiens.
In any case, you can be sure that you’ll be seeing plenty of impatiens this season. Even though many independent garden centers are backing off the plant, Home Depot—and doubtless other boxes—will be selling it.
I have ordered some semi-doubles grown by my local botanical gardens for their annual plant sale. That’s where I got them last year and they did fine.
Does anyone besides me care about this plant?