Betula (Birch) – What Is Wrong With My Tree?

The Elegant Birch Tree: A Symbol of Grace in Landscapes

Belonging to the Betula genus, birch trees captivate with their unique, often shedding, bark and refined, airy silhouettes. Indigenous to diverse regions such as North America, Europe, and Asia, they are versatile to varying climates, though they flourish most in cooler environments. Birches can manifest as petite shrubs or majestic trees reaching up to 80 feet, and their growth patterns span from upright to weeping.
Their leaves, simple yet serrated, transition to brilliant yellows come autumn.

Elongated flower structures, known as catkins, grace these trees from late spring to early summer, drawing a medley of pollinators.

The tree’s skin or bark is its standout feature, ranging in hues from snowy white to ash-gray, often shedding in delicate paper-like sheets.

Beyond their aesthetic appeal, birch trees have functional benefits: their timber is sought-after for crafting furniture, and their sap can be transformed into sweet syrup. A versatile and enchanting choice for diverse landscapes.

Birch Tree: Leave Symptoms

Birch leaves can exhibit various symptoms, including browning, curling, and spots. These issues often result from pests, diseases, or environmental stressors.

Leaves wilt and turn brown or yellow

• Bronze birch borer (Agrilus anxius): A wood-boring beetle that primarily targets weakened birch trees. The primary damage is done by the larvae, which feed beneath the bark and disrupt the flow of water and nutrients within the tree.
• Drought stress due to insufficient water supply.
• Lace bug: Can cause a range of damage to plants, including stippling, yellowing, and wilting of leaves.
• Armillaria root rot: Early symptoms often include chlorosis (yellowing of the leaves), reduced growth, wilting, and early leaf drop.
• Heart rot: The canopy may remain symptom-free or display limited signs, such as small yellowing leaves or dead branches.
• Canker (coral spot canker, perennial nectria canker): A plant disease that disrupts nutrient flow, potentially weakening or killing the plant.
• Oystershell Scale: Scales damage the foliage by killing individual cells, leading to purpling and yellowing of leaves.
• Soil compaction or poor drainage leading to root suffocation.

Blotches or spots on leaves

• Anthracnose: Brown spots or large brown blotches, encircled by yellow tissue, Brown rings with a pale center, bordered by yellow tissue.
• Birch leafminer: Amall sawfly whose larvae feed between the layers of birch leaves, forming mines that eventually turn brown.
• Rust: Rust diseases are caused by fungi that produce distinctive rust-colored spores. Affecting numerous plants, rust can hinder photosynthesis and reduce plant vigor.
• Powdery mildew: It manifests as white or grayish powdery spots, primarily on the upper surfaces of leaves and stems.
• Sooty mold: It manifests as a dark, dusty film on plant parts.

Leaves yellow with green veins (chlorosis)

• Iron deficiency, often due to high soil pH or poor drainage.
• Other nutrient deficiencies include magnesium or manganese.
• Compacted or poorly drained soils that restrict root growth.

Portions of leaves are absent or damaged

• Dusky birch sawfly: The larvae feed on the leaf tissue from the margins inwards, giving the leaves a ragged and scalloped appearance.
• Fall webworm: Consumes entire leaf sections, sparing major veins, and can strip trees of leaves in severe infestations.
• Japanese beetle: Skeletonizes leaves by consuming tissue between veins, resulting in a lace-like appearance.
• Tent caterpillar: Larvae consume complete leaf sections, occasionally sparing major veins, leading to severe defoliation in high population instances.

Webs present on the leaves

• Fall webworm: A caterpillar that spins large webs over the foliage of trees and shrubs in the late summer and fall.
• Tent caterpillar: Create silken tents as protective structures.

Leaf drop during the growing season

• Anthracnose: Infected leaves fall from tree even if still partly green
• Rust: Extensive infection may result in premature leaf browning and shedding.
• Environmental stresses like extreme heat, drought, or waterlogging.

Plant defoliated

• Gypsy moth: The gypsy moth caterpillars can cause extensive damage by feeding on the leaves, leading to defoliation and weakening of the plant

Birch Tree: Trunk and Branch Symptoms

Birch tree trunk or branch issues can manifest as cracks, cankers, and oozing sap, often indicative of fungal diseases or pest infestations.

Dead branches in canopy

• Bronze birch borer (Agrilus anxius): The primary damage is done by the larvae, which feed beneath the bark and disrupt the flow of water and nutrients within the tree.
• Root rot diseases such as Armillaria root rot: Wood is decayed, white, soft and spongy.
• Heart rot: a fungal disease that affects the inner heartwood of trees, particularly older or damaged ones. Decay-causing fungi enter through wounds or broken branches, decomposing the core while often leaving the exterior intact.
• Canker (coral spot canker): sunken, necrotic lesions on stems, branches, or trunks that disrupt nutrient flow, potentially weakening or killing the plant.

Webbing on ends of branches

• Fall webworm: A caterpillar that spins large webs at the end of branches

Atypical discoloration present on branch or trunk

• Canker (coral spot canker, perennial nectria canker): A plant disease leading to discolored sunken areas.

Fungal growth on trunk or branches

• Armillaria root rot: Clusters of honey-colored mushrooms emerge at the tree’s base during the autumn season.
• Heart rot: A wide array of fruiting bodies can be observed, showcasing diverse colors, shapes, and sizes..
• Canker rot: Caused by Inonotus obliquus, manifests as dark, sunken lesions on tree bark, often accompanied by a cracked surface. Over time, it can lead to large, brittle, charred-looking conks on trunks or branches, weakening structural integrity.

Atypical growth on trunk

• Canker rot: Caused by Inonotus obliquus, manifests as dark, sunken lesions on tree bark, often accompanied by a cracked surface. Over time, it can lead to large, brittle, charred-looking conks on trunks or branches, weakening structural integrity.
• Canker (perennial nectria canker): A plant disease characterized by sunken, necrotic lesions on stems, branches, or trunks caused by various fungi or bacteria. These lesions disrupt nutrient flow, potentially weakening or killing the plant.

Raised ridges on the trunk and branches

• Bronze birch borer (Agrilus anxius): Elevated lumps or ridges are visible on both the trunk and branches.

Holes in the stem or branches

• Bronze birch borer (Agrilus anxius): D-shaped exit holes on the trunk and branches, S-shaped galleries under the bark.
• Sapsucker: This bird drills tiny holes into the bark of trees and consumes the sap that seeps out.
• Past or current canker diseases.

For all of these symptoms, it’s essential to monitor the tree’s health and consult with an arborist or tree specialist if there are significant concerns.

The bronze birch borer is a serious pest of birch trees. You may want to consider planting disease-resistant tree alternatives to birch less susceptible to borer attacks and offer comparable aesthetic appeal with vibrant foliage, ensuring a healthy and attractive landscape.