Plants Made for the Shade
Planting shade gardens presents a few challenges, but they can be just a beautiful as full sun gardens, and will likely need less maintenance throughout the growing season.
For the last few decades, shade gardening almost always included ‘regular old impatiens.’ But Impatiens walleriana is being attacked by a disease for which there is only one cure – and that is to not plant it for a few years and hope that the pathogen dies. Impatiens Downey Mildew has wreaked havoc on gardens across the US, and devastated traditional gardens on the Cape and here on Nantucket. Like many plant diseases, the incidence of Downey Mildew will probably wax and wane for several years, causing impatiens death in its wake. This disease is carried by wind and is uncontrollable in the landscape. Impatiens planted in the landscape or in window boxes and containers will likely die without extensive fungicide use. And extensive fungicide use has already caused Plasmopara obducens, the pathogen responsible, to become resistant, as they have discovered in Europe.
High humidity, wet weather and certain temperatures are the triggers for the mildew spores to bloom. The large outbreak in 2012 was a direct result of these environmental factors. Experts suggest that the only way to reduce the incidence is to not plant this impatiens. No host, no disease.
So now what are you supposed to plant in your shade gardens? Luckily, there are a lot of substitutions. New Guinea impatiens and Divine impatiens are resistant to the disease, and they are great choices, though plant breeders are still working on achieving the fantastic color range that was available in walleriana. But let’s expand past impatiens and explore other plants that thrive in shade! How about this combination: Go-go begonias (a non-stop type) and Painted ferns or Asparagus ferns? You could try a clump of a fancy-leaved caladium. The foliage is fun and colorful. And there are also tons of new begoniasthat are not like your grandmother’s begonias! ‘Breezy’ and ‘Illumination’ both feature big fleshy richly colored flowers with large interesting foliage, and they bloom right up until frost. Torenia and browalia both bloom all summer, so pair any of these with coleus, ferns or lamium and you will have lots of annual appeal.
But don’t stop with annuals! There are lots of choices for shade perennials. An old favorite is Solomon’s Seal (polygonatum ) and in fact, the variegated form was voted as ‘Perennial plant of the Year’ in 2013. Green Solomon’s Seal and Dicentra (Bleeding Heart) complement each other with their graceful arching blooms, and the blooms appear at the same time in spring. They both are reliable, long-lived and thrive in shade. They are excellent in indoor arrangements, too. Hostas and Ferns will fill in large shady areas, and Astilbe is especially good if you have pressure from deer.
If you have been relying on Impatiens to fill your shade gardens for years, it’s time to try some different plants.