Once upon a time, now many years ago, millions and millions of impatiens were planted all across the kingdom. Their range of beautiful colors and ability to tolerate shade made them beloved by all who enjoyed their season long color. Then, along came a devastating plague, Impatiens downy mildew (IDM). Seemingly overnight, plants became yellow or spotted, then curled with a silvery “down” on the underside of the leaves. The buds, flowers and leaves quickly fell from the plants leaving beds full of naked green stems! And the townsfolk were very, very sad… until they realized there were other impatiens that were completely resistant to the scourge!
Fortunately, New Guinea Impatiens (Impatiens hawkeri, see picture below), a different species that was highly resistant to the horrible disease, was already available. Plant breeders from many different companies had been breeding and selecting for wonderful attributes such as large flowers (larger than “standard” impatiens) and great colors (scarlet, orange, pink, coral, lilac, violet white and more) for years. Not only were NGI flowers large and showy, but instead of green leaves many had leaves that were reddish-green or even had some variegation. Because different companies were breeding them, there was a wide range of different series, brand names if you will, like ‘Tamarindo’ or ‘Divine’. How to best succeed with these New Guinea impatiens (NGI)? In a perfect world they would get morning sun and afternoon shade. So yes, partial sun, partial shade is perfect. Like all impatiens, they like to be moist (not wet), especially in hot weather. They’re great for beds or containers. For those plants in containers, feeding with some water-soluble fertilizer every 2-3 weeks is fine. For people with commitment issues, consider using a season-long, timed-release fertilizer like Osmocote, which is incorporated into the soil mix at planting time and feeds for four months, essentially the whole growing season in Chicago.
And plant breeders did “standard” impatiens one better with the development of Sunpatiens (see below). Sunpatiens is the first series that, with adequate moisture, can tolerate full sun as well as partial shade. Who knew that was possible? They also tolerate high heat and humidity with grace and no reduction in performance. Like the New Guineas, don’t over-fertilize, especially with a high nitrogen fertilizer, unless you like bushy plants with fewer flowers. The color range runs the gamut from white through magenta, with stops all along the pink, orange, orchid, red spectrum. In slightly cooler summers of the upper Midwest expect the Sunpatiens Compact series to grow 18-24” tall and equally as wide. Why yes, you do space them farther apart for the same coverage as the beloved “standard” impatiens.
Still, there were townsfolk longing for the good old days of “standard” imps they grew up with. For those people, there is hope on the horizon. Cue parting clouds and an emergent rainbow! A very positive article in a recent trade publication shared the latest breakthroughs in breeding and genetic testing of a bloodline of “new, improved standard” imps. Rejoice, this impatiens are in the testing stages. So far, things look promising for a possible debut as early as 2020. Word is the colors will initially be more limited, perhaps six at the rollout. More will undoubtedly follow, but the full range that was represented at the peak of the ‘Super Elfin’ series’ popularity probably won’t be realized again due to the lack of color genetics in the disease resistant parent.
Dancing broke out in the streets. There was talk of impatiens festivals (or maybe not). And all was right once again in the shaded gardens of the kingdom!