Common Name: European black alder, European alder
Scientific Name:
Family: Betulaceae
Genus: Alnus
Species: A. glutinosa
Hardiness Zone: 3 to 7
Height: 40 to 60 ft
Width: 20 to 40 ft
Common Characteristics:
European black alder, also known as European alder, is a large and often narrow, pyramidal-shaped tree, reaching 40-60 feet at maturity. European alder often grows many suckers around the base of the tree. The leaves are large (up to 4"), simple, ovate to round with doubly toothed margins, and glossy dark green in color. The young leaves and twigs are resinous. The pink and small female catkins and the yellow-red male catkins bloom in the early spring. The fruits (strobiles) develop in the fall from the the female catkins. The fruits look like cones and contain winged-seeds which fall off the tree while the cones remain on the tree through the winter. The bark is dark brown with striping.
Where It Grows:
European black alder prefers full sun to partial shade and medium to wet soils. It can tolerate clay soils, wet soils, air pollution, and some flooding or drought. It often grows in wetlands and woodlands and can displace the native plants in these areas by growing densely and inhibiting understory growth.
How It's Used:
European black alder spreads aggressively and is considered a noxious weed in the Midwest. It tolerates many site conditions and therefore is used in areas with poor soils as it can fix nitrogen from the air. It is also used in rain gardens.
Ecosystem Services:
Smalls mammals and birds use European black alder for nesting and food.
Where It Is Native To:
European black alder is native to Europe and central Asia.
Problems:
Problems that European black alder can have are canker, aphids, leaf miner, tent caterpillars, lace bugs, and flea beetles.
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