Ironwood

Ironwood Ostrya virginianaIronwood (Ostrya virginiana) also called hop hornbeam, is a shade-loving tree of small size with a slender trunk and sparse foliage. It is found throughout Iowa from dry slopes and ridges to moist slopes in the shade of other hardwoods.

Hardiness: Zones 3 through 9

ironwood trunk showing ironwood bark
Ironwood Bark, Photo by Rebekah D. Wallace, University of Georgia, Bugwood.org

Growth Rate: Slow to Moderate

Mature Shape: Tall oval-canopied deciduous tree

Height: 30 feet

Width: 30 feet

Site Requirements: Full sun o light shade in any average, well-drained soil. Tolerant of urban conditions.

Leaves: Alternate, simple, and double-toothed with equal leaf bases

Flowering Dates: April - May

Seed Dispersal Dates: August - Fall

Seed Bearing Age: 25

Seed Bearing Frequency: Yearly

Seed Stratification: Warm stratification for 2 months at 68°F to 86°F followed by 5 months of pre-chilling at 34°F to 40°F.

While closely resembling the leaves of the elm, the leaves are more finely toothed, tissue paper-like in texture and pale green in color.  The buds are small, brown and pointed, and the twigs are much more slender than elm and shiny brown.

The fruit is clusters of leafy, pod like structures which enclose flat, ribbed, pointed nutlets. The light brown or reddish brown bark is finely ridged and covered with fine thin scales.  The ridges are never as heavy as the ridges of elm bark.  Often, the bark tends to spiral up the trunk.

summertime ironwood tree with leaves
Ironwood Tree, Photo by Paul Wray, Iowa State University

white ironwood fruit
Ironwood Fruit - Photo by Paul Wray, Iowa State University

ironwood leaves
Ironwood Leaves - Photo by Paul Wray, Iowa State University

long clusters of ironwood flowers
Ironwood Flowers, Photo by Paul Wray, Iowa State University

ironwood twig
Ironwood Fruit - Photo by Paul Wray, Iowa State University