Hop Hornbeam

Size, growth and what to expect

A young hop hornbeam stands only 10 to 15 feet tall after 15 years, well under a foot a year. Our growth estimator models it a little faster, at about a foot a year on an average site, slowing toward maturity. Most trees top out at 25 to 40 feet with a trunk under a foot through, and the crown spreads 15 to 30 feet. Trees typically live about 100 years, though one in Maine was ring-counted to 281.

Trees begin bearing seed at about 25 years. Each nut is a quarter inch long inside an inflated papery sac, and the clusters look like hops, which gives the tree its name. Its buds and catkins are a main winter food for ruffed grouse, on par with aspen and birch. The other common name, ironwood, comes from its extremely hard wood.

It grows wild from Nova Scotia and Manitoba south to Florida and Texas, scattered in the understory of hardwood forests on dry slopes, ridgetops and shallow rocky soils. It is slow to establish and does not tolerate salt.

How to grow Hop Hornbeam

Few trees are less fussy. Hop hornbeam grows in full sun, part shade or deep shade, so it fills out even under an existing canopy. It wants dry to average soil that drains, rocky ground included. At full size, keep it 20 feet from the house and clear of wires. Set trees 12 to 24 feet apart.

Plant while dormant. Saplings ship bare-root or potted, and the roots move best on a small tree. Open the hole wide and no deeper than the roots, hold the flare at the surface, and refill with what you removed. Mulch a ring with a gap at the trunk, and stake only on a windy site. Pick the hoplike clusters while they are pale greenish brown and sow the nutlets outdoors that fall, a quarter inch deep under mulch. Seedlings come up the next spring. Seed held for a spring sowing needs two to three months warm and damp, then three to five months cold.

Water weekly the first two summers when rain is short. Rabbits and voles chew the thin bark, so leave a wire cylinder on for three winters, and expect deer to rub a young stem in fall. Take the cylinder off once the bark roughens. Prune broken wood only.

Male and female catkins open together on the same tree in spring and the wind carries the pollen, so one tree sets seed alone. This tree asks for patience. Growth is slow for years, then steady, and the reward is wood so hard that ice storms seldom break it. Keep ironwood clear of drives that get salted. Male catkins hang on the twigs all winter.