Fraxinus americana is a broad-spreading, large shade tree of moderate growth rate. White Ash has excellent autumn foliage, bark character and bold texture in winter but is not urban tolerant.
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F E A T U R E S |
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Form
-large deciduous tree
-maturing at 70' tall x 70' wide
-upright rounded growth habit
-medium growth rate |
Foliage
-opposite arrangement, medium to dark green and pinnately compound, casting a dense shade
-leaflets (usually 7) are ovate and usually entire on the margins
-autumn color - vivid orange, yellow, maroon, red, purple, or combinations thereof, usually in late Sept. and completely abscised by
mid-Oct. |
Flowers
-dioecious (male and female trees)
-green to purple inflorescences in Apr. are not especially showy |
Fruit
-green changing to brown clusters of samaras on female trees, littering the ground or gutters with winged seeds in autumn |
Twig
-thick and stout stems are olive changing to brown and lenticeled
-leaf scars are U-shaped with the brown pubescent lateral buds resting within the leaf scar |
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Trunk
-gray-brown and smooth in youth, becoming very deeply furrowed and ridged in a few short years, with the ridges interlacing to form a diamondback pattern of 2" thick bark with age
-smooth gray bark persists in larger diameter branches than in Green Ash (Fraxinus pennsylvanica)
-quickly losing its central leader to yield several large upright or spreading branches for a very rounded habit |
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C U L T
U R E
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Culture
-full sun
-adaptable to soil types and soil pHs but overall not especially urban tolerant (especially to soil compaction, drought and air pollution)
-propagated by cuttings grafted onto seedling understock
-Olive Family, with several disease (leaf spots, branch cankers, mycoplasma-induced decline and dieback) and pest (oyster shell scale and wood borer) problems
-abundantly available in B&B form, including several cultivars noted for growth habit or autumn color variation |
Hardiness
-zones 3 to 9
Origin
-native to the Eastern and Midwestern U.S. and Southern Canada; a major tree of midwestern forests
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U S A G E |
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Assets
-moderately quick growth for a shade tree
-brilliant autumn color
-bold texture in winter
-ornamental bark
-symmetrical rounded shape
Liabilities
-not especially urban tolerant
-some pest and disease problems, including borers
-dense shading leads to dead stem litter from the interior of the canopy
-surface roots with age |
Function
-shade or specimen tree
Texture
-medium texture in foliage and bold when bare
-thick density in foliage and average when bare |
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S E L
E C T I 0 N S |
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Varieties
and Cultivars
- Search
OSU PlantFacts for additional plants in this species
Alternates
-large shade trees and those with excellent autumn color
-large trees that grow moderately fast |