European Alder (Black Alder)
 

Mature Size, Growth, Longevity

Average mature size of 40-60' tall and 20-40' wide. Weak pyramidal to narrow pyramidal. Fast growing in youth, 24-30" per year over a 20 year period. Tends to slow down with age.

Native Range

Species native to Europe, western Asia and northern Africa; long cultivated; has escaped from cultivation in the United States.

Flower and Fruit Details

Flowers in March before leaves. Male flowers are reddish-brown, 2-4" long catkins. Female flowers are purplish, egg-shaped. Fruits are nutlets, borne in persistent, 0.33 to 0.66" long, ovoid strobiles, on 0.5-1" long peduncles, maturing in October-November.

Leaf and Bark Features

Leaves simple, alternate, 2-4" long, 3-4" wide, dark green and glabrous above, axillary tufts beneath, 6-8 vein pairs; petiole 0.5-1" long. No fall color - leaves fall off green or brown. Bark is gray-green or greenish-brown when young, becoming brown with age.

Culture and Care

Transplants readily. Prune in winter or early spring. If used along waterways, it will seed in along the banks and eventually cover large areas. Species can grow submerged in the water. Zones 4-7. Susceptible to powdery mildew (rarely serious), cankers can be a problem, leaf rust (rarely serious), woolly alder aphid, alder flea beetle, alder lace bug, leaf miner, sawfly, and tent caterpillar.

Strengths, Weaknesses, Other Facts

The tree has distinct possibilities for extremely wet areas. Does not perform well in the heat of the South. A nitrogen fixing species.

Suggested Uses

Use in wet sites, parks, large areas.

Taxa and Plants of this Species at BCA