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Black ash (Not recommended)

Fraxinus nigra

Common names:
black ash

Content Detail

Due to its susceptibility to emerald ash borer (EAB), black ash is not recommended for planting anywhere in this region, and usually requires removal and/or replacement. Black ash is a medium-sized, native tree adaptable to wet sites. This species is native to the Chicago region according to Swink and Wilhelm’s Plants of the Chicago Region, with updates made according to current research.

  • Family (English) Olive
  • Family (botanic) Oleaceae
  • Tree or plant type Tree
  • Foliage Deciduous (seasonally loses leaves)
  • Native locale Chicago area, Illinois, North America
  • Size range Large tree (more than 40 feet)
  • Mature height 40-50 feet
  • Mature width 20-35 feet
  • Light exposure Full sun (6 hrs direct light daily)
  • Hardiness zones Zone 2, Zone 3, Zone 4, Zone 5 (Northern Illinois)
  • Soil preference Acid soil, Wet soil
  • Tolerances Alkaline soil, Clay soil, Occasional flooding, Wet sites
  • Season of interest early fall
  • Flower color and fragrance Inconspicuous
  • Shape or form Narrow, Open
  • Growth rate Slow
  • Transplants well Yes
  • Planting considerations Highly susceptible to ice damage
  • Wildlife Browsers, Game birds, Insect pollinators, Migrant birds, Songbirds
  • Has cultivars Yes

Native geographic location and habitat: 

C-Value: 10. Black ash is commonly found in wet, lowland sites. 

Bark color and texture:

The bark is light gray and loosely ridged and furrowed.

Leaf or needle arrangement, size, shape, and texture:

Compound leaves are in pairs (opposite), with 7 to 11 leaflets on each leaf. The leaves are dark green in summer, changing to purplish in fall.

Flower arrangement, shape, and size: 

Male and female flowers are on separate trees (dioecious). They are not ornamentally important. The flowers appear in spring.

Fruit, cone, nut, and seed descriptions: 

The fruit is formed on female trees only. They are winged seeds.

Plant care: 

This tree is tolerant of wet sites. It prefers a slightly acidic soil.

List of pests, diseases, and tolerances: 

Susceptibility to the emerald ash borer makes this tree unsuitable for the landscape.

Photo Gallery (4)

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