The Garden Impatiens Is Back!

Imara® impatiens. Photo: www.twipu.com

In 2013, a fast-spreading disease—impatiens powdery mildew or IMP (Plasmopara obducens)—essentially wiped the garden impatiens (Impatiens walleriana), for over 40 years the world’s most popular annual, off the horticultural map, leaving gardeners struggling to find replacements. What other annual could bloom so wonderfully in the shade?

Then, just last May, I wrote about the news that a disease-resistant strain of garden impatiens had been developed by PanAmerican Seed and was scheduled for release in 2020 or 2021. (See Are Impatiens About to Make a Comeback?)

Well, flash forward to winter 2019 and a competing company, Syngenta, has beaten them to the punch. The new variety, Imara® XDR, is already here. In fact, you can buy seeds or plants from several mail-order sources right now! Undoubtedly certain garden centers will also be selling plants of Imara impatiens this summer.

How It Was Done

No wizardry or genetic manipulation was necessary to develop Imara impatiens. Mathijs Vermeulen, Head Grower at Syngenta Flowers, explained that over 5,000 seedlings were evaluated to find a first resistant plant. Even when inoculated with the disease or grown literally next to infected impatiens plants, the plant kept blooming massively right through the summer, while other plants wilted and died within 1 ½ to 2 weeks. Several years of crossing, backcrossing and testing were then carried out until Syngenta felt it had a strain of disease resistant impatiens that was ready for the market.

Growers were able to test drive the plant last year and are thrilled with the results. Now home gardeners will be able to get their hands on the plants as well.

What to Expect

If you decided to grow Imara impatiens this summer, here’s what to expect:

• Good disease resistance
• Nice range of colors
• Excellent garden performance
• Easy to grow
• Adapted to both sun and shade
• Dense mounded plant about 12 inches (30 cm) in height and spread
• Looks and grows just like the garden impatiens you know and love.

Start seed of garden impatiens indoors about 10 weeks before the last frost date in your area. In many areas, that will be between mid-February and mid-March.

If you buy plants, don’t plant them out until all danger of frost has passed and the air and soil have warmed up.

Varieties for 2019

This year, you’ll be able to choose between 6 colors and a mix: Imara XDR Orange, Imara XDR Orange Star, Imara XDR Red, Imara XDR rose, Imara XDR Violet, Imara XDR White, plus Imara XDR Mix.

I’ve only been seeing the mix in seed catalogs, so you may have to go to your local garden center this spring if you want one of the separate colors. Or ask them to reserve plants for you now.

And in the Future?

Syngenta is not the only company working on bringing back the garden impatiens. Expect other companies to jump into the fray over the coming years with their own selections. Will we eventually see literally hundreds of varieties of garden impatiens in all sizes, shapes and colors like before? Very probably!

The garden impatiens is definitely back: enjoy!

Mail Order

Here are some of the mail-order sources for Imara impatiens seed:

Stokes Seeds

William Dam Seeds

European readers can buy Imara plants by mail from Thompson & Morgan and Van Meuwen.

If you know of any other mail order sources of Imara impatiens for home gardeners, please let me know and I’ll update this article.