Ostrya

These hardy, deciduous trees are natives of Europe, North America and Asia. These slow growing, pest-resistant trees grow up to 40 feet high with a spread to match. Their trunks are short and are covered with scaling bark. They are topped by a dense crown of ovate or oblong-ovate leaves that taper into a point. The leaves are marked with conspicuous parallel veins and have deeply serrated edges. O. virginiana, the American Hop Hornbeam, is an attractive tree that has simple, alternately arranged leaves growing from 2 to 5 inches long. The tops of the leaves are dull yellowish-green and the undersides are paler and slightly fuzzy. Male and female flowers are produced on the same tree. Male flowers are borne in 1�- to 3-inche long catkins that are suspended from the twigs. Female flowers are also produced in catkins, which are a bit shorter and erect on the branches, but eventually droop. The small, nut-like fruits are each encased by a papery, flattened, scale-like bract, and are produced in small, pendant clusters resembling fruits of the hop vine, thus the common name of these trees, Hop Hornbeam. The wood of this tree is very hard and tough and is used for agricultural implements and other purposes.

Pot Cultivation

These trees can be grown in any cool, moist garden soil that has adequate drainage. Pruning should be done in the winter or early spring. Any side branches too low on the trunk should be cut out; only one leading shoot should be allowed per tree. Older trees rarely need to be pruned.

Propagation

Sow seeds as soon as they are ripe in a compost of 3 parts loam to one part each of leaf mold and sand. Small amounts of seeds may be sown in containers, but large quantities should be sown outdoors in a prepared bed, in early spring after being stored in slightly moist sand throughout the winter. Those planted in containers should be buried in ashes out side or in a cold frame during the winter and be taken into a greenhouse, if possible, in early spring. Once the young plants are large enough to handle, they should be planted in a bed of prepared soil in the nursery. From then on, the small trees should be transplanted every other year until they are large enough for their permanent positions.

O. Knowltonii.

VARIETIES

• O. carpinifolia (European Hop Hornbeam);
• O. japonica (Japanese Hop Hornbeam);
• O. virginiana (American Hop Hornbeam or Ironwood);
• O. Knowltonii.