Dogwood is a popular landscape tree throughout Kentucky. However, once infected with powdery mildew, trees can develop an unattractive appearance. The disease is most prevalent during periods of high humidity and in landscapes with reduced air circulation. Some cultivars are more susceptible than others.
Dogwood Powdery Mildew Facts
White powdery fungal growth is the distinguishing feature of this disease (Figure 1).Symptoms on leaves include reddish-brown or purplish irregular blotches, yellowing, development of brown patches, scorching of tips and edges, cupping, curling, drooping (Figure 2) and premature leaf fall.Infection typically begins in early June and continues through September.Humidity favors disease development.Young, succulent plant growth is most susceptible.Caused by the fungi Erysiphe pulchra and/or Phyllactinia guttata.Unlikely to kill trees but may result in decreased flower production the following year and an increase in susceptibility to insects and other diseases.Management Options
Select trees with resistance to the disease, such as cultivars 'Jean's Appalachian Snow', 'Karen's Appalachian Blush', and 'Katy's Appalachian Mist', Oriental dogwood, or Cornelian cherry dogwood, which is immune to the disease.Maintain plant health by mulching to the drip line, removing dead branches, and selectively pruning to increase air movement within the tree canopy.Avoid excessive nitrogen fertilizer, heavy pruning, and excessive irrigation during the growing seasonHomeowners can apply fungicides containing myclobutanil or propiconazole. Ideal spray programs begin in May or when the disease is first detected. Always follow label directions when utilizing fungicides.For more information, contact the Pulaski County Cooperative Extension Service at 679-6361 and request the publication PPFS-OR-W-06 Flowering Dogwood Diseases.
The Lake Cumberland Master Gardeners have pine straw available for sale at the Pulaski County Extension office during office hours (M-F, 8am-4:30pm). We also have loose pine straw available.
The community is invited to evaluate the annual trial located at the Pulaski County Extension Service office. This evaluation is easy to do. Come into the office to get an evaluation form, take a walk in the garden and fill the form out, then turn it back into the office.
Join us at a program called Stump the Extension Agent - Weeds on June 20 at 6pm at the Pulaski Co Extension Service office. Bring in a weed you don't know or are having trouble with and management options will be discussed. This is a free program.
Learn about timely events or things to do in your home gardens by becoming a fan of Pulaski County Horticulture on Facebook, or following @hortagentbeth on Twitter and/or kyplants on Instagram. To get updates via text about upcoming Gardener's Toolbox classes send @gardenerst to 81010.
Educational programs of Kentucky Cooperative Extension serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expression, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability.