Lovers of Impatiens rejoice!
Gardeners here have been biting their nails since 2012, when a ravaging disease called downy mildew came to Long Island and robbed us of our beloved, go-to shade-loving annuals.
What you might not have known is that every year since, as you read annual warnings of doom in this very column, researchers have been working to develop new, disease-resistant old-time impatiens.
One new series, Imara XDR from Syngenta Flowers, was shown to be highly resistant to the disease in trials conducted in 2017 and 2018 at Cornell University’s Long Island Horticultural Research & Extension Center in Riverhead. The plants are finally available for purchase, and come in rose, red, orange, violet, white and with a patterned orange star, as well as in containers with mixed colors. Expect them to grow 12 inches tall and wide with a mounded habit, just like your long-lost friend.
This is great news, to be sure, but it comes with a catch: The folks at Syngenta tell me that “since the market for impatiens is undifferentiated [until now], plants will be sold with mostly generic tags, so Imara XDR will be hard for consumers to identify.”
To help identify the “new” impatiens when shopping, the company recommends that consumers do three things: “Shop at the big-box stores that are supplied by our top grower partners (Lowe’s, Walmart and The Home Depot all have growers producing commercial quantities going into stores now); look for very healthy plants — [Downy mildew] moves in quick, and if they plants are susceptible, they usually look pretty bad at retail; look for the tag. We do have many growers that call out varieties, even in generic categories.”
It’s not perfect, but if garden centers no longer sold the original plants (many don’t, but as of last year, some still did), there would be no confusion. I recommend asking the garden center manager if the impatiens being sold are specifically Syngenta’s Imara XDR (XDR stands for “Xtreme Disease Resistance”).
That’s important, because, although the new varieties are considered immune, downy mildew has shown no sign of retreat. Plasmopara obducens, the pathogen that causes the water-mold disease, lives in the soil (surviving from one year to the next) and is carried by airborne spores. It thrives best when temperatures are warm during the day and cool at night, further aided by rain or overhead watering, which carries spores to other areas. The disease was identified on Long Island last year, so it’s a fair assumption it’s still around.
If you were to unknowingly bring home an affected plant (which actually may appear healthy at the nursery), the pathogen would infect your soil, spread from your garden to others — and prolong the problem for everyone. So take care when purchasing seeds or plants to continue to avoid Impatiens walleriana.
Other breeders are working on their own versions of downy mildew-resistant impatiens, too. “Beacon,” bred by PanAmerican Seed, is available only in select markets this year but is expected to be rolled out nationwide in 2020.
Still an option are New Guinea impatiens (Impatiens hawkeri), which have always been immune to the disease. They can tolerate more sun than walleriana, have pointed leaves and more of a spreading habit.
A hybrid species of the New Guinea type called “Bounce,” and the larger-flowered “Big Bounce,” are not susceptible, either. Their name comes from their ability to “bounce” back from severe wilt with a simple watering.
2019 Great Long Island Tomato Challenge
It's time for the 13th annual Great Long Island Tomato Challenge! There's nothing like a homegrown tomato — and there's nothing more fun than an evening of competition and camaraderie among tomato-growing friends.
Whether you've been attending for years or are new to the game, I'd love to see you there! There is no need to register; just bring your biggest (or smallest or ugliest) tomato to Newsday (235 Pinelawn Rd., Melville) on Friday, Aug. 23, at 7 p.m. I'll weigh (or otherwise judge) your entry, and you could be named Tomato King or Queen of 2019.
The competition starts now: As you await the big day, send a photo of yourself with your tomato seedlings, plants or developing fruit — along with details about your growing techniques and varieties you're growing - to email@example.com, and you might be featured in an upcoming issue of Newsday and on newsday.com. Then come back to see what your neighbors are growing every Sunday all summer long.
Entries will be judged in six categories:
• Heaviest adult-grown tomato (ages 18 and up);
• Three heaviest youth-grown categories: 6 and younger, 7 to 12, 13 to 17;
• Smallest, all ages (measured, not weighed; must be red);
• Ugliest, all ages (named at the sole discretion of the judges).
The rules: Tomatoes must be homegrown, fresh and not previously frozen. Only those entered in the Smallest category need to be red, and stems should be removed from all entries before weighing. No purchase necessary. Additional terms and restrictions apply. See newsday.com/tomatorules for details.