Content Detail

Due to its susceptibility to emerald ash borer (EAB), white ash is not recommended for planting anywhere in this region and usually requires removal and/or replacement. 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.

  • 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 (Chicago), Zone 6, 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

Native geographic location and habitat: 

White ash is native to the Chicago area, Illinois and 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 5 to 9 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.

List of pests, diseases, and tolerances: 

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

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