Impatiens Downy Mildew

An article by Featured Retail Partner, The Farm at Green Village

A new disease is threatening impatiens. Impatiens walleriana commonly referred to as bedding impatiens; include the most common impatiens many of us use in our home landscapes as well as the rosebud impatiens (double impatiens) and yellow exotic impatiens.

This new disease, commonly referred to as Impatiens Downy Mildew has been prevalent in the NJ landscape for the past two years. The symptoms of an infected plant include: initial yellowing of leaves, followed by leaves curling downward, sometimes giving the appearance that the plants need to be watered. Infected young plants will be stunted. Under humid conditions, typical of summer seasons in NJ, plants will display a white coating on the undersurfaces of some leaves. Impatiens with downy mildew will gradually drop their flowers and leaves; eventually even the stems will collapse. It should also be noted that impatiens in hanging baskets are not protected from this disease, as infected spores can be airborne. Additionally, this pathogen over winters and presents itself in the landscape the following growing season, continuing this negative cycle.

David Brill, of The Farm at Green Village, recommends utilizing alternative shade tolerant annuals. While The Farm will still offer impatiens, all impatiens sold this spring will arrive pretreated from growers with a fungicide that has a residual of about 4 weeks. However, once planted out, a strict fungicide application schedule must be followed. The Farm will also provide signage and information increasing the awareness about risks of planting impatiens and recommended substitutes.

Many of us have grown to love and cherish this cheerful and beautiful shade tolerant flowering annual, but this does not mean that we will have to have boring, dull or flowerless shady locations this growing season.

The Farm recommends the following alternatives:

  • Wax leaf begonias
  • Caladium
  • Hiemalis begonia (non-stop)
  • New Guinea impatiens
  • SunPatiens (ignore the name! wonderful shade performer)
  • Rieger begonias
  • Coleus

So please come visit The Farm at Green Village and remember your Friends of the Frelinghuysen Arboretum membership card, which will provide a 10% discount at point of sale. For retail hours and directions visit us on the web at thefarmatgreenvillage.com or call us at 973.377.8703.

Tags: