Trees of Iowa: An Interactive Key

White Ash
(Fraxinus americana)

Leaves are 5-9 leaflets, stalked, and toothed or not toothed.

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White ash is the largest and most valuable of the ash species in Iowa. White ash is characterized by having opposite, compound leaves with 5-9 leaflets (usually 7). The leaves are 8 to 12 inches in length, with individual leaflets 2 to 6 inches in length. The leaflets have stalks that are 1/4 to 1/2 inch in length; the margins of the leaflets are mostly without teeth or only slightly toothed. The upper surfaces are glossy dark green; the lower surfaces is light green and without any hair.

White Ash LeavesWhite Ash Leaves and Bark

Twigs are moderate in diameter, gray or brown in color and have leaf scars which are half-round in shape with a conspicuous v-shaped notch in the top. The fruit is a paddle-shaped samara, which often persists on the tree into winter. 

Hardiness: zones 3 through 9

Growth Rate:
Moderate to Fast

Mature Shape:
Slightly pyramidal, upright with a rounded crown

50-80 feet

50-70 feet

Site Requirements:
Native to Iowa, ash trees grow best in full sun and moist, well-drained soils. Ash trees are tolerant of a wide range of soil conditions.

Flowering Dates: April - May

Seed Dispersal Dates: September - December

Seed Bearing Age: 20 years

Seed Bearing Frequency: Every 3 to 5 years

Seed Stratification: Warm stratification for 1 month at 68°F to 86°F followed by prechilling for 2 months at 40°F.

White ash is native over much of eastern Iowa. It is native to the Cedar River in northern Iowa, to the Des Moines River and its principal tributaries in central Iowa and to the Missouri River in southern Iowa. 

White Ash FlowersWhite Ash Fruit

White as is usually found in uplands in association with the oaks, hickories and black cherry; it also occurs on moist slopes in association with hard maple and basswood. It is not found in pure stands but most often represents a minor component of these other forest types in Iowa. It sometimes is a major component of the young age-classes of a stand because it is more tolerant of shade than the oak species. 

White Ash BarkWhite Ash Twigs

White ash wood is hard, heavy, tough and relatively straight grained used for a variety of products including baseball bats, tool handles, pallets, furniture, and many specialty uses including tennis rackets, skis, snowshoes, paddles. In Iowa it also has a high value for fuelwood because of its high density. 

White ash is considered a moderately fast growing species which will attain heights of 70 to 80 feet and diameters of 2-3 feet on better sites. White ash makes an excellent shade tree but is not used as extensively as the faster growing green ash. Its fall color is either bright yellow or dark purple. 

The winged seeds do not have high wildlife value but are utilized by a few species of wildlife and may have greater importance when other food sources are in short supply. Their usefulness is increased because they remain on the tree longer than many other food sources.


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White Ash Fruit White Ash Leaves AWhite Ash Twigs White Ash Bark White Ash Flowers White Ash Leaves and Bark White Ash Fruit White Ash Form White Ash Twig