Ostrya virginiana, Ironwood

Ironwood in fruit


Multi-stem Ironwood in front of a White Oak

Ironwood, or American Hop-hornbeam, is one of few understory trees of upland, Big Woods deciduous forest in Minnesota. In the shade of larger trees, single trunk Ironwood can grow 20 to 50 feet with trunks ranging from eight to twelve inches in diameter. Multi-stem Ironwood tend to grow shorter, up to 30 feet. Although its natural habitat is woodlands, woodland clearings, and woodland edges in climax forest communities, this species will grow in sunny conditions. It tolerates dry soil, although severe drought will affect its vigor.

Flowers are catkins in May and its hop-like fruit can set July into August. Ironwood leaves are medium green, toothed with strong venation in summer, changing to pale yellow-sienna in autumn, then strongly sienna-orange and marcescent through winter. The strong color of its clinging leaves adds much needed color and contrast to the white snow, blue shadows, and dark trunks of the winter woods.

Blooms: greenish-red, May. Fruit set in July-August

Height: 20 to 50 feet

Conditions: sun to shade, medium to medium-dry soils


Ironwood's hop-like fruit