Ash, White
Fraxinus americana
Oleaceae - Olive

Description

Leaves: Opposite; once pinnately compound; 8" to 12" long; 5 to 9 (mostly 7) leaflets; deciduous; leaflets ovate to oblong-lanceolate, 3" to 5" long, glabrous on both sides, dark green on top and lighter beneath, margins entire or barely serrate, usually short-stalked; rachis slightly grooved, glabrous; turn purple to yellow-purple in fall.

Twigs/buds: Twigs fairly stout; dark green to gray-green, occasionally purplish; glabrous; leaf scar U-shaped with deep to shallow notch across top edge. Terminal bud rusty brown, blunt, covered with 4-6 brown scales, glabrous (generally not hairy); lateral buds smaller, almost triangular.

Flowers/fruit: Flowers dioecious; small and inconspicuous, arranged in conical clusters; appear in spring before the leaves expand. Fruit a samara; 1" to 2" long; 1/4" wide; paddle-shaped in dense clusters; often clinging to twigs into or throughout the winter.

Bark: Similar to green ash but more deeply furrowed.

Wood: Important where native; like green ash in characteristics and uses.

General: A large tree native to moist sites in most of the eastern U.S. Intermediate shade tolerance.

Landscape Use: Sometimes called by the name of one of its cultivars, 'Autumn Purple' ash, this is a very desirable landscape tree. Some feel that it may be less susceptible to borers than green ash, but I''ve not seen evidence of this. I have seen several white ashes in Logan, Utah, including one about 30' in diameter and 60' tall. Should be planted more as a substitute for green ash to add diversity to our landscapes. Zones 3-9.

In the last few years an exotic pest, emerald ash borer (EAB), has been making its way across the U.S. So far it has decimated populations of ornamental and native ashes and recently was found to attack fringetree (Chionanthus spp.) as well. So far EAB has not made it to Utah, but it seems likely that it will. So, plant ashes and fringetrees with caution since they may not be around for long. Some have hope that trunk injection of insecticides may work to control the pest.

Cultivars: 'Autumn Applause', 'Autumn Blaze', 'Champaign County', 'Chicago Regal', 'Elk Grove', 'Empire', 'Greenspire', 'Junginger', 'Manitou', 'Rosehill', 'Royal Purple', 'Skycole', 'Tures'.

Characteristics

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