Content Detail

Due to susceptibility to emerald ash borer (EAB), green ash is not recommended for planting anywhere in this region and usually requires removal and/or replacement. Green ash is a highly adaptable native tree. It is very cold hardy and tolerant of a wide range of soil pH and moisture levels. 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 50-60 feet
  • Mature width 25-40 feet
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 2, Zone 3, Zone 4, Zone 5 (Chicago), Zone 6, Zone 7, Zone 8, Zone 9
  • Soil preference Moist, well-drained soil, Wet soil
  • Tolerances Alkaline soil, Clay soil, Dry sites, Occasional drought, Occasional flooding, Road salt, Wet sites
  • Season of interest early fall, mid fall
  • Flower color and fragrance Inconspicuous
  • Shape or form Oval, Round, Upright
  • Growth rate Fast
  • Transplants well Yes
  • Planting considerations Aggressive, Weak wood and branch structure
  • Wildlife Game birds, Insect pollinators, Migrant birds
  • Has cultivars Yes

Size:

Green ash grows 50-60 feet tall and 25-40 feet wide.

Native geographic location and habitat:

It is commonly found in wet, lowland sites. C-Value: 1

Bark color and texture:

The bark is light gray and loosely ridged and furrowed.

Leaf description:

Dark green compound leaves are in pairs (opposite), with five to nine leaflets on each leaf. The leaves change to yellow or yellow green in fall.

Flower arrangement, shape, and size:

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

Fruit, cone, nut and seed descriptions:

Fruit are winged seeds borne in clusters.

Plant care:

This tree is tolerant of wet sites, dry sites, alkaline soils, poor soils and wind.

List of pests and diseases:

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

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