Traditional impatiens (Impatiens walleriana) are charming little plants, prized for being one of the few blooming annuals that do well in full shade. Impatiens can create swathes of color in a landscape when planted in a garden bed, or can be a cheery addition to any container. Double impatiens are the same as traditional impatiens, but with rose-like blooms. New Guinea impatiens (I. hawkerii) are also good for shade, yet offer a more exotic look and hold up to heat better than traditional impatiens. Sunpatiens is a hybrid which does well in either sun or shade and jewelweed (I. capensis) is a native impatiens that grows in wetlands.
Part shade to full shade (2-4 hours of full sun). Sunpatiens do well in full sun to part shade.
Containers, beds, or baskets. Impatiens do well in mass plantings or part of combinations.
Prefers well-draining soil. Always use quality potting soil in containers, such as our custom soil mix. Our custom soil mix is the same soil we use to grow all of our plants, which we’ve designed to contain a blend of ingredients for optimal nutrient content, moisture retention, aeration, and beneficial microbes. Amend garden beds with compost, if necessary.
Keep evenly moist. Will quickly wilt and drop leaves if they get too dry. Avoid getting water on the leaves or keeping the soil too wet, to prevent disease.
Apply water-soluble fertilizer every two weeks throughout the growing season, or add slow-release fertilizer to the soil at planting, for about 4 weeks of coverage.
No need to dead-head. If they get too leggy or spindly, they can be cut back a bit, just above a set of leaves.
Prefer 65-70 degrees F, but can tolerate down to about 45. Many varieties stop blooming at 80 degrees or higher.
Impatiens Downy Mildew
Impatiens downy mildew is a mold that affects impatiens (Impatiens walleriana), I. balsamina, and native jewelweeds (I. pallida and I. capensis). Lower leaves of infected plants turn yellow or stippled, begin to curl, and eventually drop off. A sure sign that it is downy mildew is the development of a white powdery growth on the underside of the leaves.
The disease can be contracted through contact with infected plants or soil, or through wind-dispersed spores. There is no successful treatment for plants once they have the disease, and the disease can remain in the soil for years. Once an area is infected, it’s recommended to remove all impatiens from the area, including roots, and throw it in the trash in a plastic bag; do not compost. Avoid planting impatiens there for several years, instead using alternative shade plants such as New Guinea impatiens (I. hawkerii), begonias, coleus, iresine, torenia, or other bedding plants, which would not be affected.
For more information on impatiens downy mildew from the UW Extension, click here.
Click here to view some of the impatiens varieties available at America’s Best Flowers.