Before you Plant Impatiens this Year You MUST Read This!

The Downy Mildew disease attacking garden Impatiens has struck in 33 states including Michigan. This has surprised both scientists and plant pathologists across the United States on how quickly the disease has spread. This relatively new disease has been showing up on impatiens and was first identified in 2004.  At that time, greenhouse growers quickly tried to control the disease in their crops with fungicides but the protection only lasted so long and by the time impatiens were moved through retail outlets and planted in landscapes, there was little to no protection left.  Last year in 2012 we found downy mildew in large numbers across more than half of the United States causing havoc on landscapes and costing millions of dollars in damage.  The disease has gotten so wide spread that it has caused growers to either stop growing garden impatiens or cut back what they bring to the market by 75%.

The mildew affects all types of impatiens (Impatiens walleriana) including doubles, minis and interspecific hybrids such as Fusion.  It is however not a problem with New Guinea impatiens (I. hawkeri). The first symptoms most people notice is the yellowing of the infected plants, with tiny yellow spots on the upper leaves. When you turn those leaves over you will see the fuzzy white growth of downy mildew. This is followed by the dropping of the leaves which will eventually leave nothing but bare stems.

The disease may come to your garden on infected plants or may even just blow into your garden by the wind.  It has been shown that downy mildew can travel over 600 miles in 48 hours.

Once infected, fungicide is not useful, so you must remove, bag and seal infected plants as soon as they are noticed to avoid spreading to healthy plants.

If you had impatiens last year that were diseased, we suggest you do not plant impatiens again this year to avoid the risk. In fact; unless you absolutely must have impatiens and are willing to risk the chance of a die-off we suggest you look at the following options:

This is a list of shade tolerant annuals you could use to replace Impatiens Walleriana

Ageratum

Begonia

Caladium

Heuchera (perennial)

New Guinea Impatiens

Colieus

Fuchsia

Nicotinia

Torenia

Heliotrope

Our suggestion is for you to view each of these options on the internet to see which ones will match well in your landscape as they are not a match visually for Impatiens. One great resource can be found at http://plants.usda.gov.

Have questions or need landscaping assistance?  Please contact Beth at 734-732-8200 or http://www.landscapebeautybydesignmi.com/