Hedge care

Hedges provide privacy as a screen against prying eyes and noise, divide garden spaces or frame perennial beds as borders. How dense and healthy the plants grow is decided above all in the first years after planting – and by correct cutting.

When to trim which hedge

Deciduous hedges (e.g. hornbeam, privet) are mainly cut during dormancy, ideally in the second half of winter from mid-January to mid-March. This way the “sleeping” buds on the remaining wood produce regular, early and vigorous new growth. A second cut at the end of June – the Johanni cut – makes use of the plants’ short growth pause: the second growth phase that begins in July closes the cut wounds neatly, and the hedge quickly looks uniform again. This group also includes European beech (Fagus sylvatica), which keeps its brown leaves over winter.

Evergreen hedges (e.g. yew, Japanese holly, cypress) are cut shortly before the first new growth – a winter cut can lead to frost cracking. Unevenness can be evened out over the summer, but not on very hot days: fresh cut wounds are at risk of sunburn.

Flowering hedges should grow and bloom freely, so regular shaping is not needed. Instead, they are rejuvenated every 3–5 years by thinning, removing old, worn-out shoots completely.

Box can be trimmed from May to August – the more often, the denser and more compact it becomes. Here too, do not cut on very hot, sunny days, and take care to use preventive plant protection measures right before cutting.

The right cutting shape

For shaped hedge trimming, there are three basic cross-section shapes:

• Rectangular (box shape): the most common and easy to do – drawback: near the ground, hedges often become bare due to lack of light, especially with light-hungry plants and tall hedges.
• Trapezoidal: follows horticultural teaching, lets more light reach the lower leaves and prevents bare patches from forming at the bottom.
• Oval or egg-shaped: achieves the same effect as the trapezoidal cut; the choice depends on the style of the garden.

A taut string or a guide frame made of timber battens helps to keep shapes straight.

Regularity pays off

As a rule of thumb: the more regular the care, the more even the growth. Cutting back a hedge that has lost its shape takes more effort than regular maintenance cuts – and with some species it is even impossible. Newly planted hedges are ideally cut several times a year to encourage branching; the main shoot is left undamaged until the desired height is reached. Old, overgrown hedges can be rejuvenated by hard cutting back and will regrow from their structural shoots – but this does not apply to thuja and false cypress hedges, which do not regrow after a hard cut back.

The right tools

The choice of hedge trimmer depends on the number and size of your hedges: a box border can be cut with hand shears, while a powered trimmer is recommended for long or tall hedges. The longer the blade, the easier it is to cut straight lines – though with correspondingly more weight. Electric models are usually lighter than petrol ones (watch the cable!), and petrol hedge trimmers suit long hedges in large grounds. For very tall hedges there are telescopic trimmers, and for hard cutting back a branch lopper as well. As a general rule: good tools pay off.