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TREES & plants

Black ash (Not recommended)

A young black ash tree.

Due to 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. Currently, ash trees cannot be sold in Illinois. Check with your state for quarantine restrictions. 

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.

Botanical name: 
Fraxinus nigra
All Common Names: 
black ash
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 (Chicago)
Soil Preference: 
  • Acid soil, 
  • Wet soil
Acid Soils: 
  • Tolerant
Alkaline Soils: 
  • Tolerant
Salt Spray: 
  • Moderately Tolerant
Soil Salt: 
  • Moderately Tolerant
Drought Conditions: 
  • Intolerant
Poor Drainage: 
  • Prefers
Planting Considerations: 
  • Highly susceptible to ice damage
Ornamental Interest: 
  • Persistent fruit/seeds, 
  • Attractive bark
Season of Interest: 
  • Early fall
Flower Color & Fragrance: 
  • Inconspicuous
Shape or Form: 
  • Narrow, 
  • Open
Growth Rate: 
  • Slow
Transplants Well: 
  • Yes
Wildlife: 
  • Browsers, 
  • Game birds, 
  • Insect pollinators, 
  • Migrant birds, 
  • Songbirds
More Information: 

Tree & Plant Care

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

Disease, pests, and problems

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

Native geographic location and habitat

C-Value: 10

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.
Leaves are dark green in summer, changing to purplish in fall.

Flower arrangement, shape, and size

Male and female flowers on separate trees (dioecious).  Not ornamentally important.
Flowers appear in spring.

Fruit, cone, nut, and seed descriptions

Fruit formed on female trees only.  They are winged seeds.

 

 

Fraxinus nigra or Black ash (Not recommended)

We do not seem to have this in our living collection.