Fraxinus pennsylvanica Marsh., green ash, is a deciduous, medium-sized tree with an open, irregular crown reaching about 50 feet in height. Native to eastern North America and is fairly common west to Wyoming and Colorado along plains watercourses at elevations below 6,000 feet. The tree is fast growing on moist bottomlands, and is extremely hardy to climatic extremes once established.

Fruits are straw-colored, one-seeded, winged (samaras), 1 to 2 1/2 inches long, borne in dense branching clusters; flowers are inconspicuous, without petals, borne in dense clusters (panicles) near the ends of the twigs, male and female flowers on separate trees; leaves are opposite, pinnately compound, 4 to 6 inches long, 7 to 9 leaflets, narrowly elliptical, long-pointed, entire, bright green above, paler below; stem straight, bark thin with network of interlacing ridges, brown to dark gray, twigs smooth; roots are shallow, wide-spreading.

Fraxinus smallii Britton:
United States (North America)

Fraxinus pennsylvanica var. integerrima Fernald:
United States (North America)

Fraxinus pennsylvanica var. austinii Fernald:
Canada (North America)
United States (North America)

Fraxinus pennsylvanica Marshall:
Canada (North America)
United States (North America)

Green ash is widely adapted to soils, moisture conditions and pH found east of the Rocky Mountains. The species will tolerate seasonal flooding, but is intolerant of shading from surrounding trees. Green ash is a fairly early successional tree on most sites.

Green ash is distributed throughout the east and midwest of the United States. For a current distribution map, please consult the Plant Profile page for this species on the PLANTS Website.

Type fragment for Fraxinus darlingtonii Britton
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Verified from the card file of type specimens
Preparation: Pressed specimen
Collector(s): W. Darlington
Locality: West Chester., Pennsylvania, United States, North America

Green ash is comparatively easy to establish, and has been widely used for windbreaks in the plains and prairie states and provinces. The seedling will withstand weedy conditions, but at reduced growth rates.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 5
Species: 5
Species With Barcodes: 1

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

Green ash borer and carpenter worm can be a serious problem in this tree species. Rust and ashflower gall might cause concern in some years. Ash yellow is a disease that has been associated with sever growth reductions and/or dieback in areas of the eastern Great Plains.

Green ash is a variable species and commonly accepted botanical varieties intergrade to some extent, especially Fraxinus pennsylvanica var. subintegerrima and Fraxinus pennsylvanica var. lanceolata. ‘Cardan’ (MT) is recommended for planting in the Northern Great Plains states. Green ash seedlings are available at most commercial hardwood nurseries.

Green ash is not as rapid growing as red maple or elm, so it tends to be crowded out over time by its faster growing cohorts. Management to retain green ash includes control of competition.

Deer will browse green ash seedlings so protective netting may be required where pressure is heavy.

Windbreak: Plant green ash in the central rows of multi-row windbreaks. It can also be used for single-row windbreaks, although loss of lower branches with age reduces effectiveness.

Wildlife: Green ash is of moderate importance to wildlife. The winged seeds (samaras) are eaten by a number of birds and mammals including wild turkey and rodents. Whitetail and mule deer browse the twigs and foliage.

Recreation and Beautification: Green ash is extensively planted as a shade and ornamental tree. New clones have increased its importance in the landscaping industry.