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TREES & Plants

Ironwood

A dainty, but tough understory tree with beautiful birch-like leaves, grayish-brown flaky bark, fine-textured drooping branches, and attractive hop-like fruits. Ironwood is considered one of our toughest native hardwoods and is not only ornamental but resistant to many disease and insect problems. Excellent tree for shady or naturalized landscapes.

 

Botanical name: 
Ostrya virginiana
All Common Names: 
Ironwood, American hophornbeam, Eastern hophornbeam, Hop-hornbeam
Family (English): 
Birch
Family (Botanic): 
Betulaceae
Tree or Plant Type: 
  • Tree
Foliage: 
  • Deciduous (foliage falls off)
Native Locale: 
  • Chicago area
  • Illinois
  • North America
Hardiness Zones: 
  • Zone 4
  • Zone 5
  • Zone 6
  • Zone 7
  • Zone 8
  • Zone 9
Growth Rate: 
  • Slow
Light Exposure: 
  • Full sun (6 hrs direct light daily)
  • Partial sun (4-6 hrs direct light daily)
  • Partial shade (4-6 hrs indirect light daily)
Tolerances: 
  • Dry sites
  • Alkaline soil
  • Road salt
Soil Preference: 
  • Moist, well-drained soil
Flower Color & Fragrance: 
  • Inconspicuous
  • Yellow
Size Range: 
  • Medium tree (25-40 feet)
  • Small tree (15-25 feet)
Shape or Form: 
  • Narrow
  • Pyramidal
  • Rounded
Landscape Uses: 
  • Shade
  • Mixed border
Time of Year: 
  • Mid spring
More Information: 

Size & Form

25 to 40 feet high and 15 to 20 feet wide; pyramidal in youth changing to a small rounded tree with horizontal to drooping branches

Tree & Plant Care

Full sun to partial shade, naturally occurs in dry woodland understory

Best in slightly acid soil that is moist, fertile and  well-drained, can tolerate dry gravelly soils in partial shade once established

Difficult to transplant and slow to establish

Not tolerant of salt

Prune in late winter or early spring

Disease, pests, and problems

Not susceptible to any serious insect or disease problems

Native geographic location and habitat

C-Value: 5
Native to IL, Midwest and southeastern U.S.

Attracts birds, pollinators, or wildlife

Many songbirds are attracted to the tree for the seeds and shelter it provides.

Bark color and texture

Gray brown bark and trunk are ornamentally attractive,  which forming long  verticle shredding strips

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

Alternate, simple deciduous leaves, 2 to 5 inches long and 1 to 3 inches wide
Medium to dark green leaves with doubly serrate leaf margins and a pointed leaf tip

Flower arrangement, shape, and size

Male flowers are 1 inch long catkins, highly ornamental 

Fruit, cone, nut, and seed descriptions

Fruit is  drooping clusters at the tip of branches that look like hops, hence the common name Hophornbeam
Each small inflated sac has a hard nutlet inside each pod, fruit changes from green to tan