Maine Tree Species Fact Sheet

Common Name: White Ash
Botanical Name: Fraxinus americana
Tree Type: Deciduous

Physical Description:

Growth Habit: White ash has a medium growth rate and is found throughout the state of Maine.  It is best grown on rich, moist soils of low hills.  The dark, grayish-brown bark is thick and furrowed into closed diamond-shaped areas separated by narrow interlacing ridges.  Ash leaves are opposite, with 5-9 pinnately compound leaflets, and are 6-8 inches long.  The ovate-lanceolate leaves are dark green on top, whitish, smooth or hairy beneath and uniformly sized, and finely saw-toothed towards the tip.  In autumn the leaves turn plum colored to yellow.  The leaf petioles are stout and grooved.

Height: White ash grows to a maximum size of 100', but long-lived trees are more commonly 70-80' tall with a trunk diameter of 2'. 

Shape: White ash in the forest has a single, long trunk with a pyramid shape.  In the open, the tree tends to grow an oval crown.  Branches are evenly distributed, stout and upright with a deep “U” or “V” shaped junction to the trunk.

Fruit/Seed Description/Dispersal Methods:

White ash is dioecious and the male and female flowers develop on different trees from April to June.  The male flowers are small dense bunches with 2 or 3 stamens, but no petals and appear annually.  The females are elongated; many flowered clusters with a single long pistil that flower heavily every 2-3 years.  The fruit samara are dry, flattened, winged clusters that ripen in late summer and are shed through the autumn.

Range within Maine:

White ash is found throughout Maine up to Zone 3, in upland areas on the edges of wetlands, along waterways and fertile plains.  It does not grow in high elevations, but is found on the lower slopes of hills and mountains in mixed stands of deciduous hardwoods and evergreens.  The seedlings are shade tolerant in early years and saplings can develop under a shade canopy.  However, as the trees mature, they become shade intolerant.

Distinguishing Features:

White ash is the most common native ash of which there are 16 species in North America.  The twigs have a smooth, shiny bark, which is grayish, greenish or maroon on the surface.  The inner layer of the bark is brick red.  The terminal buds are rounded or dome-shaped.

Interesting Facts:

Ash wood is known for its strength, toughness, flexibility, lightweight, and almost white color.  It is sought after for making baseball bats and tool handles.  The wood bends well and is used in furniture, musical instruments and boats.  It laminates well, and has been used for snowshoes, tennis rackets and canoe paddles.  Because it can be burned green or dry, ash wood is valued by some people for stove wood.

Relationship to Wildlife:

White ash fruit provides food for quail, wild turkey, grouse, finches, grosbeaks and other songbirds.  Deer and moose browse on young twigs and leaves.  The juice of the ash leaves when crushed relieves the swelling and itch of mosquito bites.

Landscape Use:

White ash transplants easily.  Because of its size, it is appropriate for use in parks and larger landscaped areas, rather than house lots.  The species does best in well-drained soils rich in calcium and nitrogen, but can tolerate droughty soils as well.

Common Problems of the Tree in Maine:

White ash that grows adjacent to old farmland or pastures is prone to an "ash yellow" mycoplasm disease that blocks the phloem and creates a condition of drought stress in the tree.  Trees affected by this disease can survive in a normal year, but if dry seasons prevail they suffer severely and can die.  White ash is also susceptible to white ash borer, fall webworm and other insects.

References:

The Complete Trees of North America.  Field Guide and Natural History.  Elias, Thomas S., Book Division, Times Mirror Magazines, Inc., 1980.

The Encyclopedia of North American Trees.  Benvie, Sam, Firefly Books Ltd., 2000.

A Field Guide to Trees and Shrubs.  Peterson Field Guide #11A, Petrides, George A., Houghton Mifflin Co., 1986.

Forest Trees of Maine, 12^th Edition.  Maine Forest Service Department of Conservation, 1995.

Interview. Holleran, Robbo. Forester, April 30, 2001.

 Manual of Woody Landscape Plants. Dirr, Michael A., Stipes Publishing LLC, 1990.

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