Flowering dogwood trees are popular ornamental trees known for their beautiful blossoms in spring and colorful foliage in fall. However, like all plants, dogwoods are susceptible to diseases that can affect their health and appearance. In this article, we will discuss some of the most common flowering dogwood tree diseases, how to identify them, and the steps you can take to treat and prevent them.
Anthracnose
Anthracnose is a fungal disease that commonly affects flowering dogwood trees, particularly in cool, wet weather. Symptoms of anthracnose include irregularly shaped brown spots on the leaves, which may eventually lead to leaf blight and dieback of branches. To identify anthracnose, look for dark lesions with a purple border on the leaves and stems.
To treat anthracnose, prune and destroy infected branches and leaves to prevent the spread of the disease. Apply fungicides labeled for anthracnose prevention in early spring before new growth appears. Properly water and fertilize the tree to promote overall health and vigor, making it more resistant to anthracnose.
Powdery Mildew
Powdery mildew is another common fungal disease that affects flowering dogwood trees, especially in humid conditions with poor air circulation. Symptoms of powdery mildew include a white powdery growth on the leaves, flowers, and stems of the tree. Infected leaves may become distorted and yellow before dropping prematurely.
To manage powdery mildew, prune out infected plant parts and improve air circulation around the tree by thinning out dense branches. Apply fungicides labeled for powdery mildew control according to the manufacturer’s instructions. Water the tree at the base to avoid wetting the foliage, as overhead irrigation can promote the spread of powdery mildew.
Dogwood Anthracnose
Dogwood anthracnose is a serious fungal disease caused by Discula destructiva that specifically targets flowering dogwood trees. Symptoms of dogwood anthracnose include brown spots on the leaves with reddish-purple margins, wilting of leaves and shoots, and cankers on branches. In severe cases, dogwood anthracnose can lead to dieback of branches and even death of the tree.
To combat dogwood anthracnose, prune out infected branches and dispose of them properly. Apply fungicides labeled for dogwood anthracnose prevention in early spring when new growth emerges. Plant resistant cultivars of dogwood trees to reduce the risk of infection.
Root Rot
Root rot is a common problem in flowering dogwood trees caused by various soilborne pathogens, such as Phytophthora spp. Symptoms of root rot include wilting of leaves, yellowing or browning of foliage, stunted growth, and dieback of branches. Infected roots may appear darkened and mushy when examined.
To address root rot, improve soil drainage by planting dogwoods in well-draining soil and avoiding overwatering. Remove any mulch or debris from around the base of the tree to reduce moisture retention near the roots. Fungicide treatments may help manage root rot in severe cases.
Canker Diseases
Canker diseases, such as Botryosphaeria canker and Nectria canker, are fungal infections that cause sunken lesions or dead areas on the bark of flowering dogwood trees. Cankers can girdle branches and lead to branch dieback if left untreated. Infected trees may exhibit wilting foliage, reduced growth, and overall decline in health.
To control canker diseases, prune out infected branches below the cankered area and disinfect pruning tools between cuts to prevent spreading the disease. Maintain good tree hygiene by removing dead or diseased plant material from around the tree. Apply fungicides labeled for canker prevention as a preventive measure in early spring.
In conclusion, recognizing the symptoms of common diseases that affect flowering dogwood trees is crucial for timely intervention and effective management. By taking proactive steps to identify and treat these diseases early on, you can help protect your dogwood tree’s health and beauty for years to come. Remember that proper cultural practices, such as adequate watering, fertilization, and pruning, play a significant role in preventing disease outbreaks in your flowering dogwood tree.