White Ash
Fraxinus americana

Location in Ontario

White Ash grows throughout the Deciduous Forest Region and northward. It grows in a variety of soils, but the soil must be rich and moist. White Ash is the largest and most common of the Ash trees in Canada.

Magnificent large double White Ash, Norfolk County. Sadly, this tree is dying due to Emerald Ash Borer.

Genus Fraxinus
Leaves: Compound, opposite
Flowers: Monoecious or dioecious
Fruit: Samaras (a seed in a papery tissue)
Ontario Species: Black Ash, Red Ash, White Ash, Pumpkin Ash (Carolinian), Blue Ash (Carolinian)
Other facts:
*Ash trees are at risk to the Emerald Ash Borer (see the Tree Diseases page).
* Ash and Hickory are similar with compound leaves, but Ash leaves are opposite and Hickory leaves are alternate.
*A spring rhyme, referring to which leaves appear first; Oak before Ash you get a splash, Ash before Oak you get a soak.
In the Landscape
White Ash is a medium sized tree, growing up to 25 metres, and living to 200 years. Trees grow relatively fast, with a nice overall shape and beautiful purple-red leaves in the fall. Unfortunately it is risky to plant White Ash due to Emerald Ash Borer.

White Ash leaves are light coloured or "whitish" beneath leading to the name White Ash.
White Ash has compound leaves with 5 to 9 leaflets, usually 7. The leaves are whitish underneath. Leaves turn a beautiful red to purple colour in the fall.
White Ash bark has a distinctive diamond pattern of intersecting ridges, the strongest diamond pattern of all the Ashes.
White Ash is dioecious with male and female flowers on different trees. The flowers are small and darkly coloured, and appear in early spring before the leaves. They are wind pollinated.
White Ash seeds are Samaras which form in the summer, and fall off in the autumn. Some seeds persist into winter. Seed Production happens about every three years, after reaching an age of about 20 years.
Ash wood is hard and heavy. It is used for flooring and furniture, as well as hockey sticks, tennis rackets and tool handles.
Specific Gravity:
Janka Hardness: 1320 lb
Wood Comparison Chart

White Ash occurs as diploid (46 chromosomes), tetraploid (92 chromosomes) or hexaploid (138 chromosomes). Interestingly, the occurrence appears to be related to latitude: tetraploids occur mostly south of 35 degrees and hexaploids occur mostly between 35 and 40 degrees. Diploids occur throughout the range. Differences in ploidy appear as variations in leaves.

TREE FACT: There is some evidence that Pumpkin Ash, a hexaploid, resulted from a cross between a diploid Red Ash and a tetraploid White Ash.

Link to United States Forest Service Silvics Manual: White Ash