Hedges are vital components of gardens, creating privacy from neighbors, dulling the raucous and often continuous note of road traffic, and helping to prevent animal access. Additionally, they have an aesthetic quality, with many revealing either beautiful flowers or colorful foliage that can create very attractive backgrounds. There are even some hedges, such as the Dwarf Box (Buxus sempervirens ‘Suffruticosa’), that form essential parts of knot gardens.
For all hedges it is essential to encourage bushiness, so that the base is packed with stems and leaves. Hedges which are not pruned when young invariably have bare and unsightly bases later in their lives. When planting is in late summer or early autumn, leave the initial pruning until spring of the following year. This is because young and tender new shoots that develop from late summer or autumn pruning may subsequently be damaged by winter frosts.
The initial pruning needed by hedges can be divided into three groups (see pictures).
Immediately after planting, cut back all shoots to 6 in (15 cm) above the soil.
• Buxus sempervirens (Box)
• Crataegus monogyna (Hawthorn)
• Ligustrum ovalifolium (Privet)
• Lonicera nitida(Chinese Honeysuckle)
• Prunus spinosa (Blackthorn)
• Symphoricarpos albus (Snowberry)
Immediately after planting, cut back all leading shoots and long side shoots by about one-third.
• Carpinus betulus (Hornbeam)
• Corylus avellana (Hazel)
• Corylus maxima ‘Purpurea’
• Fagus sylvatica (Beech)
Do not prune leading shoots, but cut back untidy laterals
• Aucuba japonica (Laurel)
• Chamaecyparis lawsoniana (Lawson’s Cypress) and its varieties
• x Cupressocyparis leylandii (but only for use in large gardens and as a windbreak)
• Euonymus japonicas (Spindle Tree)
• Griselinia littoralis
• Hippophae rhamnoides (Sea Buckthorn)
• Ilex x altaclerensis
• Ilex aquifolium (Common Holly)
• Olearia x haastii (New Zealand Daisy Bush)
• Pittosporum tenuifolium
• Prunus laurocerasus (Cherry Laurel)
• Prunus lusitanica (Portugal Laurel)
• Taxus baccata (Yew)
• Thuja plicata
• Ulex europaeus (Gorse)
A-Z Of Pruning Established Evergreen Hedges
Aucuba japonica ‘Variegata’
Spotted Laurel / Gold Dust
Pruning is not usually necessary for established hedges, but use pruning shears to cut out old stems in spring, as well as those damaged by frost.
Berberis x stenophylla
Informal shrub with arching stems. No regular pruning is needed, but cut back large hedges after the flowers fade
Buxus sempervirens ‘Suffruticosa’
Use hedging trimmers to trim hedges in late summer or early autumn.
Slightly tender evergreen shrub with a dense, leafy nature. Use pruning shears to clip the hedge to shape in mid-spring. For a more formal outline, use hedging trimmers to trim it during summer.
An attractively foliaged hedge for coastal areas. Use pruning shears to trim back hedges in early or mid-summer.
Griselinia littoralis ‘Dixon’s Cream’
Prune in the same way as for Griselinia littoralis, but not quite so severely.
Ilex x altaclerensis
In mid-spring, use pruning shears to trim back long shoots and to smarten up the hedge’s shape.
Common Holly / English Holly
Prune in the same way as for Ilex x altaclerensis.
Once this hedge is established, use hedge trimmers to clip over it several times during summer.
Ligustrum ovalifolium ‘Aureum’
This plant is less vigorous than the all-green form and therefore needs slightly harder pruning during its early years. Once established, treat it in the same way as for Ligustrum ovalifolium.
In the initial year after being planted, ensure that each plant is cut back by about a half, and in the following year cut back the young growth several times. During the following years, cut back all new growth by about a half.
Lonicera nitida ‘Baggesen’s Gold’
This is less vigorous than the all-green Lonicera nitida and therefore needs slightly harder pruning over the first few years.
Use hedge trimmers to trim established hedges in mid-spring and mid-summer.
Cherry Laurel / Common Laurel
In late spring or late summer, use pruning shears to trim back long shoots. Additionally, large hedges can be cut back hard in spring.
Prune in the same way as for Prunus laurocerasus.
Renovating Ilex (Holly)
Where hedges have been neglected, they can be cut hard back in spring. Fresh shoots will develop from the hedge’s base.
Renovating Neglected Aucuba Japonica Hedges
Large and overgrown hedges can be cut back to about 2 ft (60 cm) high in spring. Although the hedge will initially look unsightly, it will soon start to develop fresh, young shoots.
Shaping the Tops of Hedges
All hedges should be trimmed, regardless of the shape of the top, so that the base is wider than the top and sunlight can reach the lower branches. Often, hedges that are trimmed perfectly vertically have the bottom shaded by the top and therefore the bottom loses its foliage and the stems can be seen.
Pruning Established Deciduous Hedges
Berberis thunbergii‘Atropurpurea Nana’
A dwarf Berberis with rich reddish- purple leaves. Use pruning shears to trim to shape in winter.
Common Hornbeam / EuropeanHornbeam
Forms a large hedge. Use hedge trimmers to clip the plants during mid- summer. Trim young hedges lightly, but established ones more severely.
Once established, use hedge trimmers or power equipment to trim the hedge in mid- or late summer.
• Philosophy of Pruning Shrubs
Reprinted with permission from Home Gardener’s Pruning: The Essential Guide to Caring for Shrubs, Trees, Climbers, Hedges, Conifers, Roses and Fruit Trees. (Home Gardener’s Specialist Guide)Pruning by David Squire and published by Fox Chapel Publishing, 2016.