“Real” Impatiens Are Back?
August 6th, 2019
Maybe I’m a little premature, but me thinks good, old-fashioned impatiens are back.
These Beacon impatiens are looking pretty good — and mildew-free — at Penn State’s Trial Gardens.
Impatiens walleriana were our top-selling annual flower up until 2012, when a deadly downy mildew disease swooped in and killed just about everybody’s plants in a matter of weeks.
Because the water mold that causes the collapse is as durable overwintering in the soil (5 years or more) as it is virile in spreading by wind, planting impatiens has been a risky/lost cause ever since.
This spring, Syngenta Flowers introduced the first new line of impatiens that purportedly has a high degree of natural resistance to downy mildew. It’s called impatiens Imara XDR.
Coming on the heels of that is another line of resistant impatiens from PanAmerican Seed called Beacon. These are a U.S./Dutch collaboration due out next spring.
I’ve been trialing Imara ‘Rose’ this season in my home garden, planted next to an older variety of cheapie rose-colored impatiens I bought at a grocery store.
The Penn State Trial Gardens in Lancaster County are trialing eight colors of Imara impatiens and seven colors of Beacon impatiens in containers alongside a few old-style impatiens for comparison.
In both places, all of the newcomers are chugging along nicely while the older types are going downhill to downy mildew.
The older ones are yellowing, stunted, dropping leaves, and displaying the telltale sign of a grayish coating on the leaf undersides. Late July is when mildew symptoms usually start to show up.
I also saw Beacon impatiens growing nicely in the trial gardens in Buffalo, N.Y., and at Burpee’s Fordhook Farm trial gardens, although those gardens didn’t have older impatiens nearby as a control.
Obviously, the downy-mildew water mold is still around, despite the fact that it has far fewer host plants to reproduce on than it did back in 2012 when so many yards had impatiens.
The older impatiens variety Super Elfin White is succumbing to downy mildew, front, while Beacon White behind is healthy in this trial at Penn State.
With disease taking down the neighbors in these trials, it’s also obvious (at least to me) that the Imara and Beacon lines really do have some superior genes that are protecting them from mildew.
Also good news is the fact that these are both seed-grown varieties that were selected with natural resistance to downy mildew, as opposed to hybrids or cutting-grown varieties.
That means both series will be less expensive to grow than most of today’s high-performing annuals, which I’ve seen priced as high as $5 and $6 per 4-inch pot.
Imara and Beacon should come in at or near the same price as most other annuals in four- and six-plant packs, i.e. in the range of $3 to $4 per pack.
Performance-wise, both Imara and Beacon look just like old-fashioned bedding impatiens and grow in the same mounding habit to about 10 to 12 inches tall.
I don’t think either bloom quite as full as the best of the pre-2012 performers, but the flowers are still covering 50 to 60 percent of the plants. Not bad at all.
I’d give the slight edge to Beacon, although there seems to be some performance differences from color to color in that series. At Penn State, Beacon Bright Red was the strongest bloomer in late July, while the Orange and Bright Orange versions were a little weaker.
This one is Imara Red.
The Imara series looked close to the same in performance across all eight colors.
After the 2012 die-off, most gardeners switched to other shade-tolerant species (coleus, begonias, torenia, browallia, etc.) or forked out higher prices for disease-resistant New Guinea impatiens (taller and pointy-leafed) or for hybrids of New Guineas and wallerianas, such as Bounce, Big Bounce, and SunPatiens.
If the trial results bear out the long-term reality, we could be back in business with reliable, affordable, and beautiful flowers for those shady spots.
Read more about Imara and impatiens downy mildew in the spring 2019 column I wrote for PennLive.