European ash

Frêne commun

Fraxinus excelsior L.Oleaceae (olive family)

Origin: Europe


European ash is a medium-sized tree, with a dense, broad, rounded crown and upward-reaching branches.

Read more about Tree, Bark, Twigs


Leaves are pinnately compound, with many toothed leaflets, and have an opposite arrangement on the branch.

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Flowers are purplish to yellow to greenish, very small with no petals or sepals, in many-flowered clusters.

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Fruits are winged seeds (samaras) borne in clusters.

Read more about Fruit


European ash is a medium-sized tree, up to 25 m (82') tall.

Branches grow upwards forming a broad, rounded crown.

Young bark is smooth and grey.

Bark on older trees is dark grey and has tight ridges.

Twigs are greyish-brown and hairless. Like other ashes, branches, twigs and leaves have an opposite arrangement.

Buds are black and hairy. Terminal bud is large and pyramid-shaped, and is usually flanked by two smaller buds.

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Leaves are 20 - 35 cm (7 3/4" - 13 3/4") long, pinnately compound, with 3 - 5 or more pairs of leaflets along a central stalk (the rachis), and one at the tip.

Leaflets are oval, 5 - 8 cm (2" - 3 1/8") long, stalkless, with pointed tips, sharp teeth along the edge, and hairs on the midvein.

As with other ashes, leaves have an opposite arrangement on the branch.

In the fall, leaves remain green, but may yellow somewhat.

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Flowers are purplish to yellow to greenish, very small with no petals or sepals, in many-flowered clusters.

Flowers are borne in spring before the leaves expand. They may be unisexual (male or female parts only) and if so, may be borne on separate trees.

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Fruits are winged seeds (samaras) borne in clusters.

Fruits are 2.5 - 4 cm (1" - 1 1/2") long surrounded by a wing that becomes papery at maturity.

Fruits mature in late summer and may remain on the tree into winter.

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European ash, sometimes called European black ash, is native to Europe and western Asia where it grows best in deep, moist, alkaline soil. It has long been planted as a cultivated tree in Europe and, to a lesser extent, in North America.

Derivation of names

The genus name, Fraxinus, is the classical name for ash. It is derived from the Greek word phraxix, meaning separation, which is in reference to the European use of ash trees as hedges. The species name, excelsior, is from the Latin for taller or higher.

Commercial use

When seasoned, the wood of European ash is particularly flexible and is therefore used for ladders, oars, airplane parts, tool handles, and joists.

The threat of the emerald ash borer

European ash, along with native ash species, is currently threatened by the emerald ash borer (Agrilus lanipennis). This insect pest, brought from Asia, was first detected in the US and Canada, including the GTA, in 2002, and has already killed millions of ash trees. Ash mortality from this pest is expected to be on the scale of the decimation of North American elms from dutch elm disease and American chestnuts from chestnut blight in the 20th century. Removing and replacing dead ash trees will cost municipalities, homeowners, and businesses millions of dollars over the long term.

Because of the threat posed by emerald ash borer, no ash trees of any kind should be planted until effective control and eradication measures are developed. Since the movement of ash wood products like mulch, firewood and logs significantly contributes to the spread of emerald ash borer, these products should not be transported from place to place.

For additional information including symptoms of infection, treatment and implications see: Natural Resources Canada factsheet and City of Toronto factsheet.

Related species

European ash can be distinguished from the native black ash (Fraxinus nigra), by fall colour and by bark. In the fall European ash leaves remain green or turn slightly yellow while those of black ash turn reddish-brown. European ash has firm bark with tight ridges, while that of black ash is soft with corky ridges that turn scaly with age.

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European ash IN TORONTO

European ash's place in Toronto's urban forest

European ash can be found in Toronto's parks and cemeteries, though it is not as widely planted as native species such as red or green ash (Fraxinus pennsylvanica) and white ash (Fraxinus americana).

Landscape value and potential for home planting

Because of the presence of emerald ash borer in our region (see above in Fascinating Facts), no species of ash should be planted at this time.

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WHERE CAN I SEE European ash?

Find trees on Tree Tour maps at Canadian Tree Tours:

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