If you haven’t heard by now, common Impatiens, Impatien walleriana, are in trouble. Lots of shade gardeners are bemoaning this right now, and wonder what should they plant instead!!??
Downy Mildew is the Culprit
First, a little background. I found out about this when I visited a client three summers ago who gardens in the shade, and took a look at all her wilting, disgusting impatiens, and was at a loss to explain their demise. After calling around to different help desks at county and state offices for gardeners, I found out that impatiens are taking a direct hit from Impatiens Downy Mildew (Plasmopara obducens), a new disease that has recently has reared its ugly head in the states, and has killed off masses of Impatiens throughout the U.S. It started as long ago as 1942, with only sporadic outbreaks, but really starting getting going in 2004. In 2011, widespread kill-offs of Impatiens were reported and things aren’t expected to get any better.
This is a relatively new disease that only targets the common Impatien, not the other Impatiens like the New Guinea, Big Bounce or Sunpatien. Sunpatien and Big Bounce are new on the market in the last few years and are husky vigorous plants, unlike the common Impatien.
If you experienced it in your annual plantings last year, then this year watch out! The pathogen overwinters handily and can persist for years. Here are the things to look for:
- Yellowish or pale-green foliage
- Downward curling of the leaves
- Distorted leaves
- White to light-gray fuzz on the undersides of the leaves. There are excellent images on the web if you search for “Impatiens Downy Mildew.”
- Emerging, new leaves that are smaller than normal and discolored.
- Flower buds that either fail to form or abort before opening.
- Stunted plants
Sounds like a horror story for any gardener who relies on Impatiens for color in the shade. And there are a lot of gardeners who plant them exclusively. So, now is the time to look for alternatives until plant breeders come up with some resistant varieties and that could be a while. There are lots of beauties out there for the taking if you know what to look for.
Alternatives for Shade Color
There are newer varieties of the old standard Lobelia that are worth a try. Many people thinkk of Lobelias as early season performers that fizzle in our heat here in the mid-Atlantic region of the U.S.. The reason these new varieties are garnering such attention is that they are showing a new heat tolerance, blooming like superstars from spring through midsummer. Cooler regions of the country will find them blooming even longer. They are tolerant of shade. Try the Laguna Sky Blue cultivar.
2. Begonias-Foliage and/or Flowers
Begonias are a huge shade loving group and I use them either for their striking foliage or colorful large flowers or both.
I love this big-leaved heirloom begonia. It has a black palmate leaf with green marbling and appealing tufted edges. Begonia ‘Black Fancy’ is a rhizomatous heirloom variety. Of course, the flowers are insignificant, but the foliage is stunning!
Flower– Pretty new to the market, this begonia ‘Bonfire’ positively glows. Easy to take care of with filtered light, it looks good in hanging baskets as well as planted into borders.
3. Fuchsia-These have elegant two-toned hanging flowers for the shade. They look good in pots and if you plant them in beds, be sure to water regularly. Fuchsia aren’t as easy to grow as Marigolds but are well worth the effort. Chillier temperatures and partial to full shade is required for the best performance of this beautiful plant so they do not do well in the south.
4. New Guinea Impatiens –The old standby New Guinea Impatiens are more tolerant of sunny conditions and are great for containers. If you plant them in the ground, be sure to add plenty of compost, water regularly, and dead head to get rid of the ugly spent blossoms.
5. Torenia (Wishbone Flower)- This is an underused plant for the shade. Tough and colorful, Wishbone Flower comes in shades of pinks, blues, and violets. It is a ground hugging plant that when happy in the shade, will produce loads of colorful oddly shaped flowers-like a wish bone!
6. Scaveola (Fan Flower)- I found out by accident that this lovely blue mounding plant is tolerant of shade. I was desperate to get some color in a client’s shady border and threw some in and it grew wonderfully. There are also some varieties in pink and white, but I love the blue.
7. Coleus – This is not your grandmother’s coleus with a limited color palette. Breeders have been very busy making new varieties for sun and shade. Take your pick and go for the colors that you like best!
8. Euphorbia Diamond Frost An annual euphorbia that resembles babys breath, Diamond Frost gives an airy light touch to shade plantings, whether in planting beds or containers.