Recently I have read a number of articles and posts about the devastation caused among Impatiens (Impatiens walleriana and related) by downy mildew. While usually just an unsightly nuisance among perennials, this strain is deadly for Impatiens. It can be treated but only if caught early and if you are willing to resort to the chemical arsenal.
This raises two questions. First, is it worth planting Impatiens in 2013? And second, what would you replace them with? My tentative answer to the first question is no. Regarding the second question, I’m not sure, though I have some ideas.
I realize that some people really don’t care. They disdain Impatiens as common, boring, etc. For myself, I do not believe that because a plant is common it is therefore of no value in the garden. I use Impatiens extensively in my shady back garden, mostly in containers but also in beds, as a filler. I also used it last year to fill in between the new perennials in the shady bed on the east side of the house.
Impatiens has several notable virtues, or at least it did until the Impatiens plague came along. First, it blooms its little head off from early summer right through frost. Second, it is not at all bothered by dense shade or by Chicago’s hot and humid summers. Third, it needs almost no attention, the main thing is to keep it from getting too dry. Fourth, it spreads nicely, creating a mounded flowery carpet. Also, it will obligingly spill over the sides of containers, and it attracts hummingbirds. Oh yeah, one other thing: they’re really cheap.
Almost all the Impatiens I plant are white, I like to have lots of white flowers in shady parts of the garden.
Despite all this, I don’t think I will plant any Impatiens this year. Just seems too risky, because once you have infected plants the disease will be in the soil, lying in wait, for Lord knows how long. The best way to be able to plant this species again is to wait out the infestations, or until the breeders come up with resistant varieties.
So what should I plant instead of Impatiens? I will probably use a mix of plants, but they all should be shade tolerant, low-growing, have white flowers, fill in nicely, and not require a lot of attention. Ideally, they will also be good for wildlife. Oh, and not too expensive. A few possibilities include:
Floss Flower (Ageratum houstonianum). Usually blue, but has white varieties. Meets all my criteria, except that in my experience this plant will not spill over the side of containers.
Saphire Flower (Browallia). There’s a variety called ‘Endless Flirtation’ with white flowers. This plant is supposed to be a good spiller. Not nearly as cheap as Floss Flower, though.
Foliage Plants. There are varieties of Coleus and Calladium with green and white or near-white leaves. Calladiums are much more expensive, though I usually plant a few anyway.
I also considered but rejected a few possibilities, including annual Lobelia (Lobelia erinus) and various types of Begonias. I like annual Lobelia, but it usually shrivels in the heat of summer. On the other hand, Judy and I just don’t like Begonias. Hard to explain, but there you are.
What about you – will you be planting impatiens this year? And if not, what will you use as a replacement?