The Cherokee Princess Dogwood, Cornus florida ‘Cherokee Princess’, is an ornamental tree known for its striking white blooms in spring, lush green summer foliage, and vibrant fall color. Despite its beauty, this tree can face challenges affecting its health.
Common Disease Problems
Dogwood anthracnose, caused by a fungus, presents as dark spots on leaves and flower bracts. These spots enlarge, leading to blighted leaves and twig dieback, causing defoliation and tree death if the infection reaches the main trunk.
Powdery mildew appears as a white, powdery growth on leaves from early summer. Severe infections can cause new leaves to scorch, twist, or become distorted. Older infected leaves may develop purple blotches that progress into dead areas, weakening the tree and reducing growth.
Spot anthracnose creates small, reddish-purple spots on leaves and flower bracts, which can cause them to wrinkle or distort when numerous. This fungal disease is cosmetic and does not seriously threaten the tree’s health.
Leaf spot diseases appear as circular or angular dark purple areas on leaves. Severely infected leaves may be reduced in size, killed, or develop holes. Cankers are sunken, discolored areas on stems and branches. These disrupt water and nutrient flow, leading to branch dieback, premature leaf drop, and reduced vigor.
Common Pest Problems
The dogwood borer is a pest that targets the tree’s vascular system. Initial signs include yellowing or thinning leaves in the crown, wilting branches, and loose or peeling bark. Coarse, sawdust-like frass may be visible near entry holes on the trunk or branches.
Dogwood club gall midge causes club-like swellings or galls on twigs. These galls can lead to twig dieback, though the damage is often localized.
Scale insects attach to plant surfaces and extract sap, leading to yellowing leaves and reduced growth. They excrete honeydew, which can attract ants and promote sooty mold growth. Severe infestations stress the tree.
Aphids are insects that cluster on new growth and the undersides of leaves, feeding on plant sap. Their feeding can cause leaves to curl, yellow, or distort. They also produce sticky honeydew, and heavy infestations can weaken young or stressed trees.
Leaf miners are larvae that tunnel within leaf tissues, creating winding trails or blotches. This damage is cosmetic and does not cause serious harm unless infestations are extensive.
Environmental and Cultural Issues
Drought stress manifests as browning along leaf edges, wilted leaves, or premature leaf color change. It occurs when water loss exceeds uptake, especially during hot, dry periods. Prolonged drought weakens the tree and increases susceptibility to other problems.
Overwatering or poor drainage can lead to root rot. Symptoms include wilting and yellowing leaves, reduced vigor, and branch dieback. These mimic drought stress but stem from excess water depriving roots of oxygen.
Improper planting depth can hinder root establishment and lead to girdling roots, which wrap around the trunk and constrict water and nutrient flow. The root flare should be visible at or slightly above ground level.
Soil pH imbalance, particularly alkaline soil, can cause chlorosis, a yellowing of the leaves while the veins remain green. Dogwoods prefer slightly acidic soil, and incorrect pH prevents nutrient absorption.
Sunscald occurs when bark is exposed to intense winter sun. This results in discolored, sunken areas, and eventually cracking or peeling bark.
Winter injury or frost damage can affect dogwoods, leading to dieback of branches or damage to buds and new growth.
Preventative Care and Solutions
Cherokee Princess Dogwoods thrive in partial shade and require well-drained, slightly acidic soil. Proper drainage is important, as waterlogged conditions can lead to root issues.
Correct planting techniques involve digging a hole twice as wide as the root ball but only as deep as the root ball, ensuring the root flare is at or slightly above ground level. Deep and consistent watering is important, especially during dry periods, to establish roots.
Applying a 2-4 inch layer of organic mulch around the tree helps conserve soil moisture, regulate soil temperature, and suppress weeds. Keep mulch a few inches from the trunk to prevent moisture buildup and rot.
Balanced fertilization supports tree health, but dogwoods are light feeders and benefit from slow-release fertilizers in early spring. Avoid over-fertilization, which can encourage excessive growth. Regular monitoring for early signs enables timely intervention.
Proper pruning involves removing dead, diseased, or damaged wood to improve air circulation and tree structure. Minimal pruning is needed, as excessive foliage removal can lead to watersprouts. Preventing physical injuries to the bark from lawnmowers or string trimmers is important, as wounds provide entry points for pests and diseases.