Preventive Care

• Healthy dogwoods have a greater chance of avoiding and recuperating from problems that lead to bloom failure than neglected, struggling trees. Grow dogwoods in full sun to partial shade. Trees in shady locations may suffer from poor flowering, so provide as sunny a spot as possible. Dogwood trees thrive in acid pH levels of 5.5 to 6.0, so test your soil and adjust with amendments, if necessary. Maintain moist, well-drained soil conditions; avoid waterlogged conditions. Irrigate the soil with approximately 1 to 2 inches of water per week if the climate becomes dry, as this could lead to a lack of flowering.
  
  

Problem

• Dogwood anthracnose disease primarily damages flowering dogwoods. Caused by the fungal pathogen Discula destructiva, also known as Discula anthracnose, this disease inhibits bloom on lower branches. Dogwood anthracnose affects dogwood at all ages, primarily in shaded conditions. As this devastating disease has wiped out up to 95 percent of a flowering dogwood tree population in affected areas, according to the University of Florida, it warrants serious attention. Alert your county extension office immediately if you suspect an infection of your trees; your quick response can protect other dogwoods in your community and region.
  
  

Damage

• Examine your trees for signs of dogwood anthracnose before attempting to treat the problem. Look for spots on leaves in a tan hue surrounded by a purple edge. Search for wilted, darkened leaves and dieback of lower branches. Contact your local county extension agent or a licensed professional for assistance in determining an accurate diagnosis. Dogwood anthracnose spots resemble those of other diseases like spot anthracnose, but infected trees may not always exhibit spots. Wait for a diagnosis before moving forward with chemical treatment. This disease leads to both bloom failure and plant death, so act quickly to prevent severe damage.
  
  

Solutions

• To control dogwood anthracnose and to increase the potential for bloom, begin with chemical-free management methods. Avoid overhead irrigation to prevent standing moisture on trees that encourages anthracnose development. Remove, gather and destroy debris and infected parts of plants to decrease disease spread. Maintain a 2- to 4-inch layer of organic mulch like pine needles on the soil surrounding your tree, but do not press mulch against tree trunks. Mulch keeps weeds at bay, stabilizes soil temperatures and retains essential moisture. For severe problems, apply a fungicide with the active ingredient mancozeb or benomyl.