3 Ways to Help Prevent Downy Mildew in Ornamental Impatiens

Impatiens are beautiful flowering plants that add bright color to your garden and are relatively easy to care for. Sadly, a new and deadly plant fungus that is specific to ornamental impatiens has emerged recently in the US that is called downy mildew. Downy mildew can present itself as yellow spots or what looks like soft grey mold on the underside of impatiens leaves and is deadly for infected plants.

At City Floral Garden Center in Denver, we know how important growing and planting impatiens can be to our wonderful customers, so we want to help you in your every effort to prevent downy mildew in your impatiens. Here are three ways you can help prevent impatiens downy mildew:

1. Choose a planting space without a huge block of shade for your impatiens. While it may seem counter-intuitive as most impatiens plants like the popular impatiens walleriana (aka Busy Lizzie) are often coached to be planted in cool, shady areas of your garden, the pervasive downy mildew has more of a chance infecting your plants in highly shaded areas. Instead, plant your impatiens in lightly shaded or filtered shade areas so as to help them keep their moisture during hot days, but not too “in the dark” during the afternoons.

2. When planting new impatiens, make sure to space them evenly apart with enough room around each plant for good air circulation to occur. Downy mildew more often occurs in crowded garden beds where the plant leaves get wet, then stay damp overnight in the cooler weather because the plants are too close to each other to dry out. Good air circulation is critical to helping prevent impatiens downy mildew.

3. After weather with cooler temperatures, check each impatiens plant for early signs of downy mildew. These symptoms can include yellowish spots on impatiens leaves, or even a slightly grey powdery look on the underside of impatiens leaves. Unfortunately, infected plants won’t recover from downy mildew, so they’ll need to pulled (roots and all) and either the entire plant bagged and thrown away (do not put it in your compost) or safely burned away from your garden beds. The sooner you catch downy mildew among your impatiens, the better chance you have to stop it from spreading among your entire garden bed.

Have more questions about downy mildew, how it affects impatiens, and what else to do to prevent it? Come into our garden center or call us at (303) 399-1177 and our employees are happy to answer all your questions!