Map showing the states infected with Downy Mildew.  Much Ado about Impatiens! 2013 Downy Mildew Update Downy mildew is still with us, overwintering in our soils, and that’s a problem for everyone who loves Impatiens walleriana, the favorite shade garden annual. Last year it spread across the northern Seaboard and through the Southeast and to Texas. Reports of the disease were also documented in California, Oregon and Washington.   The disease is spread two ways: (1) by plants that are already infected with the pathogen and purchased by consumers and landscapers who plant them in their gardens; and (2) from spores spread by rain or irrigation (which splashes spores onto neighboring soils), and by wind currents which carry the spores to new territories.  Plants infected with the disease become defoliated after being installed in the landscape, leaving nothing but withered green stalks devoid of foliage and flowers. This is known as the “green stick syndrome.” (Earlier in the growing season, infected plants will be stunted, remain small, and fail to thrive.) Infected Impatiens and all their leaves and flowers should be removed immediately and disposed of - do not compost the diseased plants, and do not replant Impatiens walleriana in the same bed, because spores will overwinter and reinfect plants again the following season.   Spores remain in the soil for years after the disease has been introduced. The pathogens, known as “oospores,” have over-wintered in Delaware and New York (Zone 5), indicating that the spores are resistant to very cold temperatures. No one has yet determined at what winter temperature the spores may die. Because the spores over-winter in the soil, they germinate again in the spring, which begins the process of infection all over again, if Impatiens walleriana are re-planted in the same location.   Once the soil has become infected with downy mildew, do not replant Impatiens walleriana in the same flower beds. It is not yet known how long the disease will remain in the soil, but it is assumed it could be many years based upon the studies at Ball Horticultural Co.  The above information was obtained from the 2013 report by Dr. Colleen Warfield and Nancy Rechcigl at ANLA, and at Ball Publishing, HERE. So what can you plant in the shade this year? Click HERE for some ideas.  

Map showing the states infected with Downy Mildew. 

Much Ado about Impatiens!

2013 Downy Mildew Update

Downy mildew is still with us, overwintering in our soils, and that’s a problem for everyone who loves Impatiens walleriana, the favorite shade garden annual. Last year it spread across the northern Seaboard and through the Southeast and to Texas. Reports of the disease were also documented in California, Oregon and Washington.  

The disease is spread two ways: (1) by plants that are already infected with the pathogen and purchased by consumers and landscapers who plant them in their gardens; and (2) from spores spread by rain or irrigation (which splashes spores onto neighboring soils), and by wind currents which carry the spores to new territories. 

Plants infected with the disease become defoliated after being installed in the landscape, leaving nothing but withered green stalks devoid of foliage and flowers. This is known as the “green stick syndrome.” (Earlier in the growing season, infected plants will be stunted, remain small, and fail to thrive.)

Infected Impatiens and all their leaves and flowers should be removed immediately and disposed of - do not compost the diseased plants, and do not replant Impatiens walleriana in the same bed, because spores will overwinter and reinfect plants again the following season.  

Spores remain in the soil for years after the disease has been introduced. The pathogens, known as “oospores,” have over-wintered in Delaware and New York (Zone 5), indicating that the spores are resistant to very cold temperatures. No one has yet determined at what winter temperature the spores may die. Because the spores over-winter in the soil, they germinate again in the spring, which begins the process of infection all over again, if Impatiens walleriana are re-planted in the same location.  

Once the soil has become infected with downy mildew, do not replant Impatiens walleriana in the same flower beds. It is not yet known how long the disease will remain in the soil, but it is assumed it could be many years based upon the studies at Ball Horticultural Co. 

The above information was obtained from the 2013 report by Dr. Colleen Warfield and Nancy Rechcigl at ANLA, and at Ball Publishing, HERE.

So what can you plant in the shade this year? Click HERE for some ideas.  

Botanical Chart: Pollination and Pollinators, University of Wisconsin.  Flowering plants are intimately tied to wind, water, and especially animals to make seeds and complete their life cycles. Showy flowers, big and small, owe their size, shape, perfume and color to the preferences of critters; insects especially may share any number of blooms from different plant species. This poster illustrates the kaleidoscopic diversity of both the flowers and their pollinators (the astute observer will note that bumblebees love blue). (Available for purchase from the University of Wisconsin.)

Botanical Chart: Pollination and Pollinators, University of Wisconsin. 

Flowering plants are intimately tied to wind, water, and especially animals to make seeds and complete their life cycles. Showy flowers, big and small, owe their size, shape, perfume and color to the preferences of critters; insects especially may share any number of blooms from different plant species. This poster illustrates the kaleidoscopic diversity of both the flowers and their pollinators (the astute observer will note that bumblebees love blue).

(Available for purchase from the University of Wisconsin.)

The Homebase Teenage Cancer Trust Garden

2012 Chelsea Gold Medal Winner:  Joe Swift

Large cedar structures, resembling vintage TV screens, are used to frame the garden rooms and create long views through a visually-connected space. The cedar framework not only provides a uniform structure to the garden, but it also creates shady areas of repose with its tall panels. Landscape materials include drought tolerant plants in a burgundy, green, and rusty-orange color scheme. The space is punctuated with copper water features to acknowledge the value of natural resources and sustainable landscapes. Plant materials were chosen for their texture and form, creating a visual feast of grasses, euphorbia, irises in a gravel base, woody herbs, and mounds of mock orange. Trees include Cornelian cherry dogwood, London plane tree, and Manchurian cherry. 

Photos:  Lisa Cox Designs

Winter Garden Foliage

Frigid winter temperatures doesn’t mean no color in the garden. Mix and match evergreens, perennials, and conifers for a luxurious winter tapestry. Many foliage plants thrive under chilly conditions ~ even snow and ice storms. Choose different textures and leaf forms for container gardens and place them near the front entry or friendship door where they will be seen throughout the winter. Keep planters evenly watered to prevent them from cracking during the constant freezing and thawing that occurs in winter months.