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European black alder (Not recommended)

Male catkins (flowers) and female strobiles (fruit) of European black alder.

European black alder has invasive traits that enable it to spread aggressively. This tree is under observation and may be listed on official invasive species lists in the near future. Review of risks should be undertaken before selecting this tree for planting sites. Growing 40 to 60 feet tall, black alder is typically tall and narrow but sometimes pyramid-shaped. It can be identified by its large, glossy green, oval to round leaves with a toothed margin; dangling catkins in early spring; and cone-like fruits, in fall. Young leaves and shoots are often sticky from a resin. The seed are dispersed by wind and, if they fall on water, can be spread for long distances. Along stream beds and in other wet areas, it can form dense groves that displace native plants. Like members of the bean family, it can fix nitrogen from the air, allowing it to colonize very poor soils. It invades woodlands and wetlands such as forest preserves where it disrupts the forest ecosystem by preventing the growth of understory shrubs and other plants. The tree was brought from Europe to the East Coast by early colonists. 

Botanical name:

Alnus glutinosa

All common names:

European black alder, European alder, Common alder

Family (English):


Family (Botanic):


Tree or Plant Type:

  • Tree


  • Deciduous (seasonally loses leaves)

Native Locale:

  • Non-native

Size Range:

  • Large tree (more than 40 feet)

Mature Height:

40-60 feet

Mature Width:

20-40 feet

Light Exposure:

  • Full sun (6 hrs direct light daily),
  • Partial sun/shade (4-6 hrs light daily)

Hardiness Zones:

  • Zone 4,
  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7

Soil Preference:

  • Wet soil


  • Wet sites,
  • Occasional flooding,
  • Clay soil

Acid Soils:

  • Tolerant

Alkaline Soils:

  • Tolerant

Salt Spray:

  • Intolerant

Soil Salt:

  • Intolerant

Drought Conditions:

  • Moderately Tolerant

Poor Drainage:

  • Tolerant

Planting Considerations:

  • Excessive sucker growth

Ornamental Interest:

  • Persistent fruit/seeds,
  • Attractive bark

Flower Color & Fragrance:

  • Inconspicuous

Shape or Form:

  • Pyramidal

Growth Rate:

  • Fast

Transplants Well:

  • Yes


  • Nesting birds,
  • Seed-eating birds,
  • Small mammals

More Information:

Native geographic location and habitat

Europe and central Asia

Bark color and texture 

Light to greenish gray

Leaf or needle arrangement, size, shape, and texture

Leaves oval to rounded, glossy green, with a toothed margin. Young leaves and shoots often sticky from a resin.

Flower arrangement, shape, and size

Male flowers in dangling catkins, yellow-red, in early spring before leaves appear.  Female flowers small, pink, egg-shaped.

Fruit, cone, nut, and seed descriptions

Fruit are cone-like structures.


Location of Alnus glutinosa (European black alder (Not recommended)) at the Arboretum