Ash Trees in Eugene: A Valuable Native Tree Facing New Threats

Ash trees have long been an important part of the landscape in Eugene and throughout the Willamette Valley. Native Oregon ash (Fraxinus latifolia) thrives in wet soils, floodplains, riparian corridors, and seasonal wetlands. These trees provide critical wildlife habitat, stabilize streambanks, and create cooling shade across urban and natural environments.

In Eugene, ash trees are commonly found near creeks, wetlands, and low-lying areas where winter moisture accumulates. Their broad canopy, fast growth, and adaptability have also made them popular landscape and street trees for decades.

However, ash trees across Oregon are now facing a major threat from the invasive emerald ash borer (EAB), a destructive beetle that attacks and kills ash trees by tunneling beneath the bark and disrupting the flow of water and nutrients. Emerald ash borer was first confirmed in Oregon in 2022 and continues spreading across the state.

Many Oregon ash trees are also showing stress from drought, flooding changes, soil compaction, fungi, and heat-related decline. Symptoms often include canopy dieback, dead upper limbs, epicormic sprouting, and thinning foliage.

Proper arborist care can help extend the lifespan of healthy ash trees. Structural pruning, deadwood removal, mulching, soil management, and early pest monitoring are becoming increasingly important in Eugene’s urban forest.

At  Wolfpack Tree Care, we help property owners evaluate ash tree health, identify decline symptoms, and safely manage hazardous trees throughout Eugene and the surrounding Willamette Valley. Whether your ash tree needs pruning, risk assessment, or removal, working with an ISA Certified Arborist can help protect both your property and the long-term health of the urban canopy.