Pruning hornbeam: when and how do you do it?

Hornbeam ( Carpinus betulus ) looks a lot like a beech hedge (but it isn't) and is a beautiful, medium-high tree or hedge plant, with green catkins in the spring and winged nuts in the fall that you will definitely recognize. But how and when should you prune hornbeams for the best result? You can read all about it in this article.

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Because of its dense growth, a hornbeam provides a lot of privacy and shelter in the garden . To promote full growth and for a neat and tidy appearance, it is important to prune hornbeams regularly. Otherwise, they will quickly reach sky-high and turn into unruly undergrowth.

A good time to prune hornbeams is between mid-summer (end of July-August) and winter. Winter is best: then it is the rest period and you avoid heavy bleeding of the plant.

Depending on your goal, pruning once a year is sufficient. A hedge or standard tree can be pruned a second time, just after the first growth spurt in May-June, so that it stays in shape.

Please note: hornbeams and beech hedges are often confused. However, they belong to two different families. A hornbeam is related to the birch ( Betulaceae ), while the beech hedge is related to the beech ( Fagaceae ). Read here when and how to prune a beech hedge .

You can prune a hornbeam in different ways: as a hedge plant, as a columnar tree, a tree on a trunk or as a (woven) espalier tree. Below we explain step-by-step how to do this.

Hornbeam is a perfect hedge plant, because it looks neat and grows quickly – up to 50 cm per year. A good hedge offers privacy, borders your garden in a natural way and keeps out wind and/or bright sun. For all kinds of animals, such a hedge is also an important sheltered spot. Carpinus betulus (common hornbeam), but also Carpinus caroliniana or Carpinus orientalis are often seen as hedges.

Follow these steps to prune a hornbeam hedge:

Cut away all diseased, damaged and dead branches . This is the basic rule for all your pruning and keeps the plant healthy.
Remove branches that rub against each other , as these can damage and weaken the plant.
Determine the shape. For a tall hornbeam, it is wise to prune the sides at a slight angle, with the bottom wider than the top. This allows light to reach all sides and any snow will slide off easily. You can make a template from cardboard or plywood as a guide when pruning. Work from bottom to top.

With a low hornbeam, it is often nicer to make the top (and sides) perfectly straight. You do this by stretching a string between two sticks. Make sure that the string hangs at the same height everywhere: measuring is knowing!

Trim the hedge into shape. If you opt for an electric hedge trimmer, use one with an approved circuit breaker and never use this tool in the rain. Do not lift your electric hedge trimmer above shoulder height, but use a sturdy stepladder. Don't forget your safety glasses. Or opt for a manual pruning shears, because you can work more precisely and the leaves of your hedge are less damaged. Cut back each overlong shoot to two or three leaves from the main branch. Cut diagonally next to a bud, with the lowest point closest to the bud.

If you are working with a hedge trimmer, make sure that you keep the blades of the shears parallel to the hedge and work flat and evenly. Make a wide cutting movement: follow the desired line and avoid cutting into the hedge.

Don't prune too low. It's better for a hedge to be too high than too low. As contradictory as it may sound, height makes a space seem larger, while a low, shabby hedge makes everything around it seem smaller.
Take care of your hedge after pruning. Give it some organic fertilizer and a mulch layer, so it will recover quickly.

A hornbeam on a single trunk with side branches from bottom to top is called a columnar tree. This is how you approach columnar pruning:

First cut away all diseased, damaged and dead branches.
Remove branches that grow too close together or on the central leader.
Remove strongly ascending branches or prune them back to a node.
Always cut back at an angle to buds that face outwards.
If side shoots grow stronger on one side, top the shoots on the weaker side to encourage growth.
Remove side shoots or new growth at the base and, if necessary, remove any lower branches that hang to the ground.