Black Alder
Black Alder (Alnus glutinosa) – The Black Alder is a deciduous tree from the birch family and is a native of Europe, northern Africa and western Asia. As a member of the birch family it is related to the birches, hornbeams, filberts and hophornbeams as well as the alders. It was introduce to North America a long time ago and today is grown as a shade tree in urban areas or at wet sites, such as ponds, creeks, drainage ditches, etc., where it thrives and provides both erosion control and ornamental appeal.

Its leaves easily flutter in the breeze and cutleaf forms are available that have deep sinuses giving them a much finer texture. In addition, columnar forms exist for narrow spaces.

The black alder is adaptable to a wide range of favorable or harsh environmental conditions. It prefers moist to wet soils of variable pH that are rich and deep, but adapts to average or poor soils that are dry in summer. Growth is especially rapid in occasionally wet to permanently wet areas, such as floodplains, streambanks, and ditches. Black Willow is a good companion tree with a much finer texture. It is a good pioneer species of cut-over sites, and will self-sow to form a colony of saplings within a few years of initial seed production. It grows in full sun to partial shade and is found in zones 4-7.

The Black Alder, while capable of having a few minor disease and pest problems, is usually trouble-free.
 

Summary

Shape: Oval or rounded, erect or spreading, covering an extensive area
Leaves: Round to ovate dark green. Bronze or no change in fall
Flower / Fruit: Prolific brown cone (1/2 – 1.5 inches) in fall, winter or summer
Growth Rate: Rapid
Height: 60 feet
Spread: 25 feet
Zone: 4 to 7
Light: Full sun to partial shade
Soil Type: Prefers moist and wet
Comments: The immature bark found on the limbs is dark gray interrupted by long dark fissures. This becomes black plates and scales with age on the trunk, exposing a lighter gray to gray-brown interior bark

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