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White ash is very susceptible to the emerald ash borer (Agrilus planipennis) and is not recommended for planting anywhere in this region. It usually requires removal or regular insecticide treatments. White ash, a native woodland tree found throughout the Midwest, had been used extensively as a shade and street tree. 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.

To find suitable replacements for this tree, go The Morton Arboretum’s tree and plant finder.  Before purchasing or planting, be sure to check for any local or state guidelines on any selected species, and ensure that this plant is suitable for its habitat by checking its attributes at or

  • 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 50-80 feet
  • Mature width 50-80 feet
  • Light exposure Full sun (6 hrs direct light daily)
  • Hardiness zones Zone 3, Zone 4, Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
  • Soil preference Moist, well-drained soil
  • Tolerances Alkaline soil, Clay soil, Dry sites, Road salt
  • Season of interest mid fall, late fall
  • Flower color and fragrance Inconspicuous
  • Shape or form Round
  • Growth rate Moderate
  • Transplants well Yes
  • Planting considerations Weak wood and branch structure
  • Wildlife Game birds, Insect pollinators, Mammals, Migrant birds, Sapsuckers, Songbirds
  • Has cultivars Yes

Highly susceptible to the following diseases and pests:

Emerald ash borer


White ash is a large tree growing 50 to 80 feet tall and 50 to 80 feet wide.

Native geographic location and habitat: 

White ash is native to the Chicago area, Illinois, and most of North America. C-Value: 5.

Bark color and texture: 

The bark is light gray and loosely ridged and furrowed.

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

The compound leaves are in pairs (opposite), with five to nine leaflets on each leaf. The leaves are dark green in summer, changing to purplish in fall.

Flower arrangement, shape, and size: 

The 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 are winged seeds, borne in clusters.

Plant Care:

White ash is tolerant of wet sites, dry sites, alkaline soils, poor soils, and wind.

List of pests, diseases, and tolerances: 

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


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