Why Your Dogwood Has Smaller Leaves on Upper Branches

Understanding Leaf Size Discrepancies in Dogwood Trees

A homeowner in Maryland noticed a puzzling pattern on their established dogwood: lush, large leaves on lower branches but significantly smaller foliage higher up. Both leaf sets appeared healthy with no signs of disease or insect damage. The lower branches also produced an unusual number of small new shoots. Two years prior, nearby pines that had shaded the dogwood were removed, exposing the tree to direct sunlight for much of the day. The tree initially thrived with vigorous growth and dense foliage, but the leaf size disparity emerged later.

Diagnosis: Girdling Restriction

The stark difference in leaf size between upper and lower branches strongly suggests a physical restriction—likely girdling—somewhere along the trunk. Girdling occurs when something (a root, wire, twine, or even damaged bark) constricts the vascular tissue, impeding the flow of water and nutrients to the upper canopy. The lower branches, receiving adequate resources, produce large leaves and excessive new growth, while the upper branches are starved, resulting in stunted foliage.

Recommended Actions

• Inspect the trunk carefully for any constricting objects, circling roots, or bark damage at the base and along the main stem.
• Remove the restriction if found and feasible. Circling roots may require careful excavation and cutting.
• Fertilize appropriately to help compensate for nutrients not being produced by the compromised upper limbs. Use a balanced, slow-release fertilizer formulated for trees.
• Monitor water needs—the tree may require more consistent moisture now that it's in full sun, but avoid overwatering.

Long-Term Considerations

Dogwoods are naturally understory trees that prefer dappled shade. The sudden transition to full sun may have accelerated stress, making the tree more vulnerable to girdling issues. Mulch around the base (keeping it away from the trunk) to conserve moisture and moderate soil temperature. If the restriction cannot be located or resolved, consult a certified arborist for a professional assessment.