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
Ash  trees have opposite compound leaves. Ash can be monoecious or  dioecious depending on the species. Seeds are contained in a single winged samara (a seed in a papery tissue). Ash wood is valued for its strength and hardness. Black, Red and White Ash grow in Ontario, as well as two Carolinian species, Pumpkin Ash and Blue Ash. Unfortunately, the Emerald Ash Borer has killed millions of Ash trees (see the Tree Diseases page). Black Ash has been the most susceptible to the insect, while Blue Ash shows some immunity.

??Red Ash or White Ash?? They are hard to tell apart, except in fall when Red Ash has yellow leaves, and White Ash has reddish-purple leaves. White Ash leaves have whitish undersides, and upper branches that are smooth. The leaf scar is "C" shaped.

TREE FACT: Ash and Hickory are similar with compound leaves, but Ash leaves are opposite while Hickory leaves are alternate.

TREE FACT:  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.

TREE FACT:
White Ash leaves are light coloured or "whitish" beneath leading to the name White Ash.


Small White Ash, University of Guelph Arboretum

 

Leaves
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.
Bark
White Ash bark has a distinctive diamond pattern of intersecting ridges, the strongest diamond pattern of all the Ashes.
Flowers
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.
Seeds
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.

Wood
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:
0.60
Janka Hardness: 1320 lb
Wood Comparison Chart

Genetics
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.


White Ash,  University of Guelph Arboretum

Link to United States Forest Service Silvics Manual: White Ash

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