The Useful Hornbeam

Hornbeams trained or pleached into an archway in Duncan Gardens, Manito Park, Spokane WA.

The hornbeam can be trained into a solid wall or even into an archway like these in Duncan Gardens (Manito Park) in Spokane WA.

The European Hornbeam (Carpinus betulus)* is a decorative and versatile stem in the garden.  This tree serves well as a street tree due to the narrow habit that won’t tangle with vehicles.  It is gaining popularity locally for use in commercial plantings as well, so those are the most likely ways that you will recognize this tree.

This tree is even more talented than those applications suggest.  If you have visited Spokane Washington’s famed Duncan Gardens in Manito Park, you may well have entered that garden from the East or West entrances and walked under a green archway.   That arch is formed of hornbeams.  When two trees are bent toward each other and woven together as one, they are referred to as “pleached”.  They are also referred to as elegant and beautiful.  Hornbeams may be sheared, making them quite popular for decorative purposes in formal gardens.

Hornbeam hedge newly planted.

Hornbeams have been planted closely to form a dense hedge as they mature.

A complete privacy wall may be formed with the hornbeam.  The wall can be sheared if there is too little room to allow the trees to reach mature size. Shown here is a newly planted hornbeam hedge.  Trees planted were 2″ caliper approximately 15′ tall.  They were planted fairly close since these are intended for a sheared hedge.  We did not want to wait 5 years or more for the hedge to completely fill in, though it will take time for the density to develop.

The width of the hornbeam at maturity varies according to the cultivar selected.  ‘Frans Fontaine’ and ‘Fastigiata’ are more commonly offered cultivars because they are more columnar in habit than the species.  ‘Fastigiata’ will gain width with age, but that is a very long process.  Of course, if the intent is to shear a hedge or archway, it makes no difference which cultivar since the growth habit will be managed.  When sheared, the trees will become very densely branched and foliaged.  The species will grow to approximately 40′ tall and 30′ wide, but this is a very long process to reach sizes of that magnitude, 20 years or more in our climate.  When pruning a hedge of hornbeam, the height should be selected to be tall enough to serve the purpose of privacy and the visual effect, but only that tall.  Obviously, a bigger, taller hedge or arch is more work to maintain and requires more equipment to keep it in reach.

The trees are long lived and have few pests.  The wood from the tree is very hard (Carpinus lumber is sold as ironwood) so is used infrequently since it is difficult to work. Life span is 300 years or more.  It is used in some decorative applications and Wikipedia makes the point that it is sometimes used to make chess pieces.  You’re probably better served with a beautiful hedge than the chess set, but either way, the European Hornbeam is a special tree.  Speaking of special, we still have one of the weeping form of this tree available.  That’s a treasure.

Two hornbeams shown in front of a white fence.

These two European hornbeams have been growing about 10 years in this location. They remain narrow trees without shearing.

* American Hornbeam (Carpinus caroliniana) does not share the elegance of Carpinus betulus, so it is otherwise excluded from this discussion.  It is a fine tree in its own right, and ‘Native Flame’ has mildly red fall foliage.   The wide branching and comparatively unkempt look makes it unsuitable for the applications described above.  All photos and discussion pertain to the European hornbeam, Carpinus betulus.