by Marian Parsley, Behnkes Manager of Annuals
Impatiens are getting a lot of attention these days and it’s not the kind of attention gardeners want to hear. You may not be aware of the problem, but our most beloved shade annual is at risk from a new fungal disease.
The symptoms of the disease, which is called Downy Mildew, begin as slightly off-color foliage (slight yellowing) and slight wilting/curling down of foliage. If weather conditions are favorable, the disease continues to progress, causing all of the leaves and flowers to drop off, and ultimately, the plant dies. The disease affects the standard, seed-grown impatiens; there are some other types of impatiens that are resistant to the disease (see below).
Although commercial growers can control the disease in their greenhouses through application of chemicals, this is not practical in the garden center or for the homeowner. We have decided not to carry the traditional impatiens plants at our garden centers until the plant breeders develop disease-resistant strains. Rest assured that this is a high priority in our industry.
All is not lost; there are many alternatives to old-fashioned, seed-grown impatiens. Listed below are some suggestions for some wonderful plants for you to try in your shade garden.
Disease Resistant Impatiens:
- Sunpatiens and New Guinea Impatiens–Neither is susceptible to Impatiens Downy Mildew so they’re an excellent alternative. Sunpatiens are more vigorous than the traditional New Guinea series and will bloom in both sun and shade. The key to growing any New Guinea Impatiens is providing ample water.
- Divine Series New Guinea Impatiens–Delivers outstanding color options and garden performance, heat and drought tolerant. Provides masses of flowers all season long.
- Classic, Old-fashioned Wax Begonias–Wonderful in mass plantings, color until frost and perform well in sun or shade. Low maintenance.
- ‘Big’ Begonia–They look like a wax begonia but are the size of the dragon wing-type begonia. The flowers of the Big Begonia stand atop the foliage in addition to the sides of the plant making it ideal for the landscape.
- Dragon Wing Begonia—simply one of the most beautiful begonias ever! Large red blooms on wing-like light green foliage. Spectacular in the sun or shade garden.
- ‘Sparks Will Fly’ Begonia–A real stunner in the garden or patio shade containers; gentle orange blossoms, beautiful dark green almost bronze foliage, mounding growth habit.
- ‘Whopper’ Begonia… Extra large blooms, huge plants with shiny bronze foliage. Minimal maintenance requirements. Makes a bold statement in the shade garden.
Tuberous Begonia: An old favorite, large camellia-like blossoms, green or bronze foliage. Wonderful in the shade garden.
Caladiums: Showy, tropical looking foliage with unique patterns, excellent choice for containers or the shade garden.
Coleus: A classic shade-lover in a variety of colors and shapes.
Torenia: Also known as the wishbone flower because if you look closely in the center of the flower there appears to be a wishbone. Great color choices, including beautiful blues—a color not found in impatiens.