Flowering dogwood trees are prized for their beautiful blooms and elegant appearance in landscapes. However, these trees are susceptible to various pests that can wreak havoc on their health and aesthetics. In this guide, we will explore some of the most common pests that affect flowering dogwood trees, how to identify them, and the best treatment options available.
Dogwood Borer
Identification: Dogwood borers are small beetles that lay their eggs on the bark of dogwood trees. The larvae then tunnel into the tree, causing damage to the inner wood of the trunk and branches. Signs of a dogwood borer infestation include wilting leaves, sawdust-like frass around entry holes, and visible entry holes in the bark.
Treatment: To combat dogwood borers, it is essential to keep trees healthy through proper watering and fertilization. Infested branches should be pruned and destroyed. In severe cases, insecticidal sprays may be necessary to control the borer population.
Scale Insects
Identification: Scale insects are tiny pests that feed on the sap of dogwood trees, causing yellowing leaves, stunted growth, and sooty mold growth on foliage. They appear as small bumps or scales on the branches and stems of the tree.
Treatment: Scale insects can be controlled through natural predators like ladybugs or lacewings. Horticultural oils or insecticidal soaps can also be used to smother and kill scale insects. Systemic insecticides can be applied to the soil to target scale insects feeding on sap.
Powdery Mildew
Identification: Powdery mildew is a fungal disease that affects many ornamental plants, including flowering dogwoods. It appears as a white powdery substance on the leaves and stems of the tree, leading to distorted growth and reduced flowering.
Treatment: To prevent powdery mildew, avoid overhead watering and promote good air circulation around the tree. Fungicides specifically designed for powdery mildew can be applied to infected trees according to label instructions.
Anthracnose
Identification: Anthracnose is a fungal disease that causes dark lesions on leaves, stems, and flowers of flowering dogwood trees. Infected leaves may drop prematurely, leading to defoliation and reduced tree vigor.
Treatment: Prune out infected branches and improve air circulation within the tree canopy to reduce anthracnose spread. Fungicide applications may be necessary during periods of high humidity or prolonged wet weather.
Japanese Beetles
Identification: Japanese beetles are voracious feeders that can skeletonize leaves and flowers of dogwood trees. They are metallic green with coppery-brown wings and feed in groups during the summer months.
Treatment: Handpick Japanese beetles off the tree early in the morning when they are less active. Insecticidal sprays containing neem oil or pyrethrin can be used to control Japanese beetle populations effectively.
Aphids
Identification: Aphids are small insects that feed on sap from tender new growth of flowering dogwood trees. They can cause leaf curling, yellowing, and sticky honeydew residue on foliage.
Treatment: Natural predators like ladybugs and lacewings help control aphid populations. A strong blast of water from a garden hose can physically dislodge aphids from the tree. Insecticidal soaps or horticultural oils can also be used for severe infestations.
In conclusion, proper identification of pests affecting flowering dogwood trees is crucial for implementing effective treatment strategies. Regular monitoring of tree health and early intervention can help prevent pest infestations from causing significant damage. By following the guidelines outlined in this article, gardeners can protect their beloved flowering dogwoods from common pests and ensure their continued beauty in the landscape.