Native Plant of the Month: Oregon Ash

Photo of Oregon Ash.

Common Name: Oregon Ash 

Binomial Name: Fraxinus latifolia 

Soil Type: Prefers loose, damp soil 

Sunlight: Sun to part shade 

Plant Type: Medium to large tree 

Form: Symmetrical, broadly spreading crown   

Foliage: Deciduous 

Fruit/Flower: Yes, both 

Growing to around 70 feet (and sometimes over 80 feet) tall in ideal conditions, the Oregon Ash may only grow to 25 feet in dry soils.  The only ash native to the Pacific Northwest, the Oregon Ash is commonly used for conservation and restoration projects in wet/riparian areas.  Local wildlife, including birds and squirrels, also use the tree to their advantage, hiding amongst the dense foliage or eating the seeds of the fruit (called samaras).  The wood is also traditionally used to make baseball bats, skis, oars, and other sporting goods, as well as flooring and cabinetry.   

The compound, opposite leaves are actually quite large and made up of 5 to 9 oval leaflets that can grow up to 5 inches long.  The deciduous leaflets start as bright or olive green with smooth margins, tiny hairs on the bottom, and turn a beautiful yellow color in the fall.  Though the male and female flowers are found on separate trees, they both bloom in clusters before the leaves start emerging in spring.  The samaras, the Oregon Ash’s one‐winged, single‐seeded fruit, are said to resemble canoes. 

This Native Plant of the Month has been brought to you by the City of Beaverton’s Landscape and Urban Forestry Department