Ostrya - HopHornbeam

The Ostrya's are a family of 10 species of trees that are related to the Birch. Hop Hornbeams make great shade trees and should be much more widely planted. They are native of woodlands of temperate regions of the Northern Hemisphere. They grow best in fertile, well drained soil in both sun and shade. They are very tolerant of drought once established but not compactiion or salt. Hop Hornbeams are also rarely bothered by insects or disease.
The fruits on the Hop Hornbeam are bracted seed clusters that look very similar to the Hops used in making beer hence the name.
Seeds should be planted in pots protected from extreme cold and germinate in the spring..

Ostrya carpinifolia ( European Hop Hornbeam )
Native to most of southeastern Europe as well as Turkey; this is usually a medium-size tree that is conical in youth becoming rounded with age. The fastest growth recorded is 50 x 33 feet in 20 years and the largest trees on record reach 80 x 73 feet with a trunk diameter of over 5 feet.
The double-toothed, pointed, ovate leaves are up to 6 x 2.5 ( rarely over 3.5 ) inches in size. The lush deep green foliage turns golden-yellow during autumn, coloring later than Ostrya virginiana.
The flowers and fruit are similar to Ostrya virginiana. The yellow, hanging, male flower catkins, borne during mid-spring, are up to 4 inches in length.
The bark is brown to gray and scaly.
Hardy zones 3 to 9; it grows very well in most of eastern North America, the Pacific Coast and in western Europe.

* photo taken on 4th of July 2010 in Washington, D.C.

* historic archive photo

Ostrya chisoensis ( Chisos Hop Hornbeam )
Native to elevations of 4500 to 7000 feet in Big Bend National Park in Texas; it is exceptionally drought tolerant and grows smaller to only 40 x 25 feet; though has the potential to reach 47 feet with a trunk diameter of a foot on excellent sites.
The finely double-toothed, curlved, ovate leaves are up to 2.5 x 1.3 inches in size. The hairy foliage is deep green above, hairy pale green beneath.
The fruit clusters are up to an inch in length.
The branches have a fine, delicate appearance.
The brown bark is also very attractive. It is smooth on young trees later becoming shaggy with thick, long narrow strips.
Very rare and native only to heavily shaded drainages in the Chisos Mountains in southwestern Texas. It should be tested as an ornamental tree in dry climate regions ( likely hardy zones 5 to 8 ).

Ostrya japonica ( Japanese Hop Hornbeam )
A vigorous, rounded, deciduous, large tree that is native central China, Korea and northern & central Japan. This is the largest of the HopHornbeams and is capable of reaching as much as 110 x 60 feet with a trunk diameter up to 4 feet.
The toothed, ovate or oblong leaves are up to 5 x 1.8 inches in size. The deeply-veined foliage is soft hairy at first, turning to glossy deep green above, pale green felted beneath.
The flowers appear during late spring. The fissured bark is dark brown. The twigs are grayish-brown.
Hardy zones 5 to 8 ( it has survived in zone 4b Dominion Arboretum in Ottawa, Canada but frequent winter dieback has reduced it to a multi-stem shrub ), thriving very well in both eastern North America, the Pacific Coast and in western Europe.

* historic archive photos

Ostrya knowltonii ( Knowlton's Hop Hornbeam )
Also native southwest of the range of Ostrya virginiana, from mountains of Utah and Colorado; south to Arizona to southwestern Texas. Rare and widely scatterred in the wild and rarely cultivated; though an EXCELLENT ornamental tree for dry climates. It reaches up to 30 feet tall and wide or somewhat larger on ideal sites. Some records include: largest on record - 51 x 47 feet with a trunk diameter of 3.5 feet.
The curled, oval leaves are up to 1.8 inches in length. The foliage is deep green above and hairy beneath; turning to golden-yellow during late autumn.
The brown flower catkins are short, up to an inch and are appear as the tree leafs out.
The brown fruit cones are up to an inch in length.
The twigs are hairy and slender.
Hardy zones 6 to 8, it is exceptionally drought tolerant.

* historic archive photo

Ostrya rehderiana ( Rehder Hop Hornbeam )
Also called Tianmu Ironwood. A medium size tree, reaching up to 70 feet tall and wide with a trunk diameter up to 3.5 feet. It is is only distributed in the west of Tianmu Mountain in northwest Zhejiang Province. Moderately fast growing, on ideal sites it may grow at a rare up to 2 feet per year.
The toothed, oblong leaves are up to 6 x 2.5 ( usually 4 x 2 ) inches in size. The attractive foliage is luxuriant bright green.
The flowers appear during late spring.
The rough bark is gray.
Only hardy north to zone 6; this tree is endangered with extinction with only 5 trees left in the wild.

* photos taken on Aug 25 2011 @ Scott Arboretum, Swarthmore, PA



* excellent photo link
http://www.arkive.org/ostrya/ostrya-rehderiana/image-G82011.html

Ostrya virginiana ( Eastern Hop Hornbeam )
Native to central and eastern North America ( from central North Dakota to southeast Manitoba to Thunder Bay, Ontario to Batchewana, Ontario to Haileybury, Ontario to southern Quebec and all of Nova Scotia and New Brunswick south to eastern Texas to far northwest Florida to central North Carolina ); this tree is typically conical in youth becoming rounded at maturity. A separate population is native to southwest South Dakota and northern Nebraska; this could be valuable for selection for drought resistant shade trees and shelterbelts. In the Windsor/Essex County, Ontario region; it was abundant in the Amherstburg and Point Pelee areas, the Lake Erie islands as well as the Ohio shore during the 1800s. It occurred sporadically at Detroit, Michigan during that time. Seedlings grow moderately fast - even in shade reaching up to 7 feet in 5 years on average. Typically maturing around 40 feet; on ideal sites it can grow much larger and the largest trees on record approach 90 feet tall; 110 feet wide with a trunk diameter of 4 feet. The Eastern Hop Hornbeam is very long lived up to 300 years though after 100 years of age they become very slow growing so that these trees never compare in size to similarly aged Oak. The shade cast by the dense canopy is very deep. An elegant tree that looks good in all seasons.
The toothed, ovate leaves are up to 5 inches in length ( though I've measured 8 x 4 inches on vigorous shoots on trees in the Canard River Valley near Amherstburg, Ontario ).
They are dark green above and paler below; turning brilliant clear yellow in autumn.
The early spring flowers appearing with the foliage during spring are yellow catkins.
They are followed by fruit clusters up to 2 inches long that ripen to light brown in the fall.
The twigs are very slender like that of the Birch.
The brown bark is also very attractive. It is smooth on young trees later becoming shaggy with thick, long narrow strips.
The wood is hard and very heavy ( 50 pounds per square foot ).
Extremely cold hardy thriving from zone 2 to 9; this tree reaches up to 33 x 34 feet in North Dakota and even grows far outside its native range in Saskatoon on the Canadian Prairies. Seed source not from Manitoba and Minnesota is considerably less hardy on the northern Great Plains. Rare in cultivation; it should be planted much more. While it is a very attractive tree; the Hop Hornbeam is rarely seen along highways as road salt kills it. It is also very sensitive to sulfer / nitrogen oxide, chlorine and flourine. The good news, well sited hophornbeams are generally healthy and resistant to insects, disease, ice damage and deer browsing. An excellent tree for small back yards, patios, golf courses and parks.

* photo taken by W.D. Brush @ USDA-NRCS PLANTS Database

USDA-NRCS PLANTS Database

* photos taken in Columbia, MD




* photo of unknown source on internet

* photo taken on 4th of July 2010 in Washington, D.C.

* photos taken on August 2 2010 in Bayfield, Ontario


* photos taken on August 4 2010 @ Birnam Woods Arboretum, Stratford, Ontario



* photo taken @ U.S. Botanical Garden, Wash., DC on Aug 25 2014

* photos taken on July 27 2015 in Bayfield, ON

* historical archive photos

* photos taken on Oct 21 2014 @ U.S. Botanical Gardens, Washington, DC

* photos taken on Nov 27 2015 @ Hickory Run State Park, PA

* photo taken on Jul 18 2017 @ Dominion Arboretum, Ottawa, ON

* photos taken on Jul 19 2017 @ Rideau Hall, Ottawa, ON

* photos taken on Aug 24 2017 @ U.S. Botanic Garden, Wash. DC.

* ostrya virginiana in Wallacetown, ON

* photos taken on July 13 2021 @ Hershey Gardens, Hershey PA

* photos taken on July 9 2022 in Bayfield, ON

* photos taken on July 9 2023 @ Scenic Caves, Collingwood, ON

* photos taken on July 10 2023 @ Collingwood Arboretum, Collingwood, ON

* photo taken on Aug 24 2024 @ Howard County Conservancy, Woodstock, MD

USDA-NRCS PLANTS Database / Herman, D.E., et al. 1996. North Dakota tree handbook

'Autumn Treasure'
A moderate growing, narrow-upright form, reaching up to 45 x 25 feet in 25 years, eventually larger.
The deep green foliage turns to golden-yellow then drops cleanly during autumn.
Hardy zones 4 to 8

* photos taken on Oct 22 2024 @ Howard Comm. College, Columbia, MD

'Sun Beam'
More upright and pyramidal in habit than the species. It averages 40 feet in 35 years, eventually larger. This cultivar was developed by North Dakota State University for use on the northern Great Plains.
The deep green foliage turns to golden-yellow then finally coppery in color during autumn with about half the foliage remaining on the tree.
Hardy zones 3 to 6, it is difficult to root cuttings but if can be done during mid-summer.

OSTRYOPSIS
Ostryopsis davidiana
A medium-sized, deciduous shrub, reaching up to 10 ( rarely over 5 ) feet in size, that is native from north-central China to Manchuria. It is often planted for erosion control in its native range.
The double-toothed, ovate leaves are up to 2.3 x 2 inches in size. The leathery foliage is luxuriant bright green.
The flowers appear during early summer.
They are followed by tasty and edible hazelnuts, borne on clusters up to 2 inches long.
The twigs are brown. The older branches are gray.
Hardy zones 4b to 7 ( estimate but it has thrived at zone 4b Dominion Arboretum in Ottawa, Canada ).