Species descriptions

The following section describes the species used or found in hedges, with details on their habit, history and management. Site factors are given in the table below. For full descriptions and colour photos of these species, refer to one of the many field or pocket guides available. For the history and folklore of native and naturalised plants, Flora Britannica (Mabey, Richard, 1996) is a valuable reference.

Table 5.1: Hedging species for different uses

Table 5.2: Hedging species - soil and site factors, planting distances

Thorny and prickly species

Three of these species, hawthorn, blackthorn and holly, in that order, are the mainstays of the stockproof hedge. These three species are described first below, followed by other species which may be used, depending on the situation.

Hawthorn (Crataegus spp)

There are two British species of hawthorn: the common hawthorn (Crataegus monogyna), and the woodland hawthorn (Crataegus laevigata). The two species readily hybridise. The common hawthorn is also called May, quickthorn, quick, thorn or whitethorn.

The common hawthorn was much less common in the past, but was grown and planted in huge numbers during the Enclosure movements of the 18th and 19th centuries, when over 200,000 miles of common hawthorn hedge was planted. It remains the most widely planted hedging shrub for stockproof hedges. Where the much rarer woodland hawthorn is still found in hedges, it may indicate woodland relict hedges, as it is naturally a species of mature woods. Woodland hawthorn flowers in April, earlier than common hawthorn, and has clusters of about 10 flowers, compared with the clusters of 20 or more on common hawthorn. Woodland hawthorn is the less thorny of the two species, and its distribution is restricted to central and south-eastern Britain.

Common hawthorn or May is associated in folklore with May Day, although it normally flowers around the middle of May, depending on location, altitude and prevailing weather. The reason for this discrepancy is thought to be the change from the Julian to the gregorian calendar in 1752, when the dates 2-14th September were omitted. From then on, natural events were dated 11 days later than in the old calendar, with ‘May Day’ becoming 12th May (Mabey, Richard, 1996). ‘Ne’er cast a clout till May is out’ refers to the blossom, not the month.

If left to grow freely, woodland hawthorn remains a bush of less than about 30’ (10m), while common hawthorn becomes a real tree up to 60’ (18m) tall, with a well- developed crown. For hedge management, the two species can be treated the same. Hawthorn is undoubtedly the most useful hedging plant under the widest conditions and forms of management. It grows in nearly every soil and situation, except high altitudes and in deep shade. It can be planted as close as 4” (100mm) for maintenance by trimming, or up to 3’ (1m) or more apart when it still forms a stockproof hedge if regularly laid. The only caution is not to plant it near apple or pear orchards, since it is associated with fireblight disease in these trees.

Hawthorn is nearly impossible to kill by trimming, laying or even regular hard cutting. Most hedge layers prefer it to all other species, since it is supple, easy to cut, tends not to break off easily, and has gnarled bushy ends to hold the pleachers in place.

Blackthorn or sloe (Prunus spinosa)

Blackthorn grows more slowly than hawthorn, but forms an impenetrable hedge when well established. Bushes reach 3-10’ (1-3m) in height and are thickly branched from the ground, although the bases of the branches tend to be bare of thorns, making trimmed blackthorn better against cattle than sheep. It grows in the heaviest clays, and stands any amount of wind and salt spray.

Some hedgers consider blackthorn even better than hawthorn for cutting and laying, since the upper part of the branches are even thornier, and there is usually plenty of brash to help keep stock away from the shoots. It cuts and lays as does hawthorn, possibly even more easily, but rather than sprouting from below the cut stem, it tends to send up suckers from the roots (p72). For this reason it spreads and can soon form dense thickets if not controlled, but at the same time, it is one of the best plants for filling up gaps.

Blackthorn is disliked by some hedgers because they claim the thorns are more hazardous than those of other species, as they are covered with algae which can cause a wound to go septic. The thorns are very brittle and tend to break off and fragment in the wound, making removal difficult.

Blackthorn, especially when allowed to grow into impenetrable thickets, provides cover for many birds. It is favoured by nightingales for nesting, and by shrikes for their ‘larder ’. Blackthorn is the food plant of the larvae of the brown and black hairstreak butterflies. Blackthorn often acts as a ‘nurse’ for smoothwood seedlings, protecting them from grazing animals. Sloes are gathered for the making of sloe gin.

Holly (Ilex aquifolium)

Holly makes the best evergreen hedge since it is sturdy and stockproof, but it is slow growing, taking up to ten years to make a 6’ (1.8m) hedge. It is especially suited to light, peaty soils, but will grow anywhere other than wet clays. Holly is very tolerant of shade, and is the best plant for forming hedges under the shade of other trees. It is also good for gapping, since it ‘follows on’ well from thorn.

When laying holly you should treat it like other prickly species. It is very brittle and can be easily damaged if laid in frosts. Some but not all hedgers say that it sprouts poorly and tends to rot at the base after laying.

Holly has been widely used in the past as a marker tree, to mark boundaries, stiles, points where field drains emerge into ditches and as sightlines for winter ploughing. It is frequently seen as a hedgerow tree, grown as a standard with the rest of the hedge trimmed around it. The reason for its use as a marker tree is probably because holly is easy to recognise in all seasons, even at a distance. However in some areas there are strong superstitions against cutting down holly, which may of course have been the cause of, or resulted from, its use as a marker. Trimming it for animal fodder was common, and there is a long tradition of using holly for a winter decoration. Holly is a very good shelter tree, as it takes a long time for rainfall to penetrate the canopy, and it is apparently favoured by cattle as a calving site (Mabey, Richard, 1996).

Myrobalan or Cherry plum (Prunus cerasifera)

Myrobalan is a naturalised tree, introduced fromAsia many centuries ago. It grows fast and vigorously, making a hedge in three or four years, and eventually becoming a large bush or small tree up to 25’ (7.6m) high. It occasionally bears fruit, which is red or yellow and crisp-fleshed. It can make a stockproof hedge, although the spines are not nearly as numerous or closely spaced as those of blackthorn, and it tends to get thin at the base.

Myrobalan thrives on a variety of soils, provided they are not too dry, but does not like exposed positions.

Bullace (Prunus domestica ssp insititia)

Bullace is a close relative of blackthorn, with white flowers in early spring, but instead of thorns it has occasional short shoots which form thorn-like growths. The fruits are like large sloes or dark-fruited damsons. It may be native to British woodlands, or it may be an ancient cross between the blackthorn and an introduced sweeter- fruited plum from Asia. There are so many varieties of relict or bird-sown gages, ‘prunes’ and damsons found growing in the wild that they are possibly best all treated generically as ‘wild plums’. Bullace is found in some southern and Midlands hedges, and it can be cut and laid as blackthorn.

Crab-apple (Malus sylvestris)

The true wild crab-apple is a comparatively rare tree of old hedges and woods, but ‘wildings’ or chance seedlings of domestic apples are numerous. The true crab-apple is spinier than other varieties, and forms a round, dense crown if left to grow. All wild apples can be laid, but are best used in combination with other species since they are not so impenetrable as the thorns. They are mainly found in West Midlands hedges and were apparently more common in the last century. They should not be used near fruit, since they are susceptible to insect pests and diseases which can damage fruit crops.

Brambles and briars (Rubus and Rosa spp)

Although generically distinct, these plants are managed as if they were identical. Usually they are cut out of the hedge along with other choking ‘weeds’, but in regions where tree growth is stunted and haphazard they may be kept in the hedge to add extra protection. In upland Wales some hedgers weave them in among the pleachers, saying that sheep won’t eat the ‘picks’ and therefore will keep away from the sprouting shrubs as well. In exposed parts of the South West, turf hedges are occasionally crowned with dense rows of nearly pure bramble. Its advantage is that it ‘keeps down and keeps thick’. In this case it is left to its own devices, since the more its stems reroot, the more impenetrable becomes the barrier. Dog-rose (Rosa canina) and sweet briar (Rosa rubiginosa) have pink flowers and hips attractive to birds, and are usually welcome in a ‘wildlife’ hedge.

Smoothwood species

Smoothwood shrubs seldom make up a whole hedge except in certain soils and on exposed sites where the thorns or holly cannot thrive. Most often they are mixed or form short lengths of a single species within a mixed hedge. When hedges are laid, smoothwood is cut out in favour of thorn if there is a choice. When needed it is cut and laid as thorn, but more densely, to compensate for the lack of thorny brash.

The species below are native or naturalised species, listed in alphabetical order by common name. Smoothwood species are commonly planted for garden hedges, because of their ornamental appearance, and because they respond well to frequent trimming, producing a neat, dense hedge. Smoothwood species may also be planted in ‘wildlife’ hedges, but are not usually planted in farm hedges, because their lack of thorns reduces their effectiveness against stock. Some are also either palatable to stock and so get damaged, or are palatable and poisonous. Farm hedges which are mainly smoothwood will need fencing to be stockproof against cattle or sheep, and to prevent the animals browsing the foliage and young shoots.

Many native smoothwood species occur in old hedges, either as woodland remnants, or because they have seeded into the hedge. Some may also have been deliberately planted, either as the most suitable plant for a particular situation, or because they were the only plants available to transplant from nearby woods.

Alder (Alnus glutinosa)

Alder makes quite a good hedge in damp locations near streams or wherever the water table is constantly high, and is tolerant of a wide range of soils apart from acid peat. It has nitrogen-fixing root nodules, and often grows successfully on reclaimed land. It is very fast growing in suitable conditions, and is tolerant of coppicing, laying and trimming. It is rarely eaten by rabbits or stock.

Ash (Fraxinus excelsior)

Quicker growing and more thickly sprouting than the thorns, ash is disliked for these reasons when it competes with other trees. Stockproof hedges of pure ash do exist, but must be maintained by frequent laying.

When possible it is best to cut it out of the stock hedge. Some hedgers say that cattle eat ash shoots more readily than those of most species. Ash is slightly more brittle than thorn, and although a softer wood, it is somewhat shorter-grained. This makes it harder to cut than thorn when large.

Beech (Fagus sylvatica)

Most Midlands hedgers consider beech a garden plant, to be trimmed but not cut and laid. When trimmed, it retains its withered leaves and loses them only just before the buds burst the next spring. In Wales and the South West it often occurs intermixed with other hedge shrubs, and is treated as they are. In some upland areas, notably Exmoor, beech is extremely important as a shelter hedge on high banks, as it tolerates high altitudes and exposed situations.

Beech thrives on sand, chalk, limestone or other well- drained soils. Spring frosts can damage the young foliage, and it is not a good stock barrier, as both cattle and sheep find the foliage and shoots very palatable. Beech hedges also tend to spread widely unless kept closely trimmed or laid. However, with careful management it can be kept narrow and thick at the base, and grown to any height up to 15’ or more.

Beech is fairly shade tolerant, but is not very successful in smoky conditions. Beech wood is hard, tight-grained and slightly brittle, but it splits cleanly and responds quite well to laying. Where survival is difficult, beech becomes twisted and gnarled, and this improves its qualities as a hedging shrub, since it stays tight and retains more brush around the stem.

Box (Buxus sempervirens)

Box is a small evergreen shrub, seldom growing over 10’ (3m) high, found wild in a few scattered places on chalk and limestone in southern england. It is widely grown as a garden hedge plant, but should never be used in farm hedges as it is poisonous to stock, particularly if they have access to withered clippings left after trimming.

Dogwood (Cornus sanguinea)

Dogwood is a common plant of chalk downs, and also grows well on soils of the Old Red Sandstone. It makes a dense, tough, shrubby hedge, but suckers to form small thickets and quickly seeds into abandoned pastures. For this reason, it is a weed of some downland farms and nature reserves, where it is controlled as much as possible. It has colourful red spring twigs and autumn foliage, and its black berries are attractive to birds.

Elder (Sambucus nigra)

Elder grows very quickly, up to 4’ (1.2m) a year, compared to 1’ 6” (450mm) or so for thorns. It quickly outcompetes neighbouring plants, forming loose, brittle growth which is not stockproof, and rapidly regrows if coppiced. Elder should be grubbed out from stockproof hedges during hedge laying, but is likely to seed back into the hedge with time. Near the sea, and in exposed uplands it can be used as a screen.

Elm (Ulmus spp)

Elm has always been common in hedges, because of its habit of spreading by suckers. Hard cutting, or felling of larger trees stimulates the plant to regenerate freely from the roots. In this way, hedges may become dominated by elm, with the reduction of other species. Elms were also widely planted in hedgerows during the middle and late enclosure movements, to provide farm timber.

There is probably only one native species, the Wych elm (Ulmus glabra), other elms being early introductions from the continent. In periods of warmer climate, and in southern England, elms may set seed, which has given rise to a large number of hybrids. During cooler periods, when the elm only spreads by suckering, particular hybrids have then spread through hedges to form locally distinct types. One study, in Essex, identified 27 different ‘village types’ (Mabey, Richard, 1996).

Dutch elm disease, which killed most of the mature elms in Britain in the 1970s and 80s, has had periods of similar virulence in past centuries, but the elm has been able to survive through its habit of suckering. The disease is caused by a fungus (Ceratocystis ulmi) which blocks the tree’s conductive tissue, causing crown dieback and rapid death. The fungal spores of the disease are spread by elm bark beetles, which breed beneath elm bark, and feed on twigs in May, thus spreading the spores. Once the mature dead elms have been felled or lost their bark, the breeding habitat for the beetle is lost, and at the same time, the elm may regenerate from suckers. Healthy growth may continue for 10-15 years, until the bark on the stems is thick enough to support breeding populations of beetles, when the disease may again spread. Other factors are also at work, such as the appearance of new strains of the fungus which vary in their virulence and their response to other organisms.

In spite of its great contribution to the landscape as a hedgerow tree, the English elm (Ulmus procera) and its variants were never a favourite with farmers. Elms have extensive root systems which rob moisture and nourishment from the fields, as well as invasive suckering growth. They cast heavy shade which competes with crops, and have a habit of unexpectedly dropping large limbs from apparently healthy mature trees.

It is not worth purchasing so called ‘resistant’ elms for planting. Elms have survived through previous setbacks and will no doubt continue to do so. With climatic warming, it seems likely that elms will go through a period of seeding and hybridising.

Elm is reasonable for laying, as it is slightly ‘leathery’, and tends to ‘hang on’ rather than to break off under the weight of the cut pleacher. While Dutch elm disease is still active, laying and trimming to keep the plant small helps prevent further spread of the disease, while maintaining elm as a habitat for other less troublesome organisms.

The White-letter Hairstreak butterfly is dependent on elm, where it lays its eggs during July and August, on the scar where the current year ’s growth joins last year ’s growth. The larvae do not hatch out until February or March, and then pupate, emerging as butterflies in July and August. Whilst the adults prefer mature elm for egg laying, larvae have been found on shrubby hedgerow elms about 20ft (7m) high. Small elm hedges can provide a corridor for females to find new egg-laying sites.

Hazel (Corylus avellana)

Hazel is a good hedge plant on chalk and other drier soils, where it grows strong and sturdy. When coppiced or laid, hazel produces straight shoots from the base, with an open pattern of growth and little side branching, so the shrub is not effective as a stock barrier. Hazel can be laid when growing in a mixed hedge, but a hedge of mostly hazel is not worth laying, and should be managed by coppicing, which will also produce a useful crop of poles. The hedge should be fenced as necessary, and the hazel left to grow for about 10 years before being coppiced again. Hazel should not be top-cut since this does not encourage bushy growth, but merely spoils the crop of coppice poles.

Hornbeam (Carpinus betulus)

Hornbeam is a good hedge plant which thrives in a variety of soils and situations. Atrimmed hornbeam hedge resembles beech in many ways, including that of retaining its dead leaves during winter, but can be distinguished from beech by its serrated leaves. It has advantages over beech in that it is frost proof and stock do not eat it, but hornbeam provides less shelter. Hornbeam withstands hard cutting, grows well under dense shade and makes an excellent firewood. It can be grown as a ‘garden hedge’, kept thick by regular trimming, or mixed with thorns and other hedge plants, and managed by trimming and laying.

Hornbeam hedges can be kept low, or grown into tall thin screens to shelter hops or fruit, or to provide shade. Hornbeam responds well to training and clipping. Pleached hornbeam hedges, which are in effect an ‘aerial hedge’ grown on clear trimmed stems, are a feature of formal gardens. In germany hornbeam is sometimes trained so that the plants cross one another at a 60 degree angle. The bark is cut away where the stems touch, and the stems are bound so they graft together to make a living fence.

Field maple (Acer campestre)

Field maple is common in the south and west, where it grows to 25’ (7.6m) if left uncut. It is a tough shrub, which withstands exposed positions and salt air. It is found with other shrubs in mixed hedges, but does not make sufficiently dense growth to be stockproof on its own, although it forms fairly dense growth when trimmed. It is hard and brittle, but can be laid successfully.

Oak (Quercus spp)

Oak is a frequent hedgerow tree, and its seedlings may survive in the hedge and be managed along with other species. It can be damaged by late spring frosts, and should not be planted near orchards as it is a host to a number of insect pests of fruit trees. Although it doesn’t form very thick growth, oak is a nice tree for hedge laying, being ‘soft’ and easy to lay without breaking.

The introduced holm or evergreen oak (Quercus ilex) makes a good evergreen screen and tolerates shade and salt wind, but is not suitable for farm hedges due to its weak, open growth.

Poplar (Populus spp)

Some of the poplars make good screen or windbreak trees, although they are not suitable for trimmed or stockproof hedges. The introduced white poplar (P. alba) is very hardy, grows well in sandy soils and doesn’t mind salt spray. It sends out quantities of suckers which can be useful for screening purposes, but may be a nuisance elsewhere. It should be lopped at 6-8’ (1.8-2.4m) to stay thick and hedgelike.

Spindle tree (Euonymus europaeus)

A fairly vigorous native green-stemmed shrub, which colours in autumn and bears unusual pink capsules, each containing four bright orange berries. Spindle is naturally found on well drained soils in the south, particularly in hedgerows and woods on downland. It is ideal for planting in informal ‘wildlife’ hedges and woodland corridors on suitable soils, but growth is too sparse for it to form a major component of a stockproof or trimmed hedge.

Sweet chestnut (Castanea sativa)

Sweet chestnut was brought to Britain by the Romans, and is long naturalised, especially on neutral soils in the south east. It is not suitable for a trimmed hedge, but coppices well and is a useful species for a wildlife hedge.

Wayfaring tree (Viburnum lantana)

This shrub is common in hedges and scrub on chalk soils, where it grows to about 20’ (6m) high if left untrimmed. It is light demanding, and does not thrive under the canopy of other trees. Wayfaring tree regrows well after hard cutting or trimming, although growth is too open to be stockproof. It’s a good shrub for a wildlife hedge, as it bears berries, red turning black, which are attractive to birds.

Willow (Salix spp)

Willow can make a rough hedge or windbreak on wet ground, but is not suitable for a stockproof barrier, as growth is open and the foliage and shoots are readily grazed by cattle. It can be laid in a mixed hedge, but tends to be rather springy and difficult to secure neatly.

Hedgers usually cut out willow where they can, but sometimes Welsh hedgers keep it because it regrows quickly under difficult conditions. It can be useful for filling a gap where the ground is too wet for other species. In East Anglia and other peaty areas, willow is often used in windbreaks where it is coppiced or pollarded periodically. Willow resprouts readily from all sizes of cuttings, up to the size of fencing stakes, if stuck in the ground the same way up that they were growing. Unless you want to create a willow hedge, don’t use willow as stakes in a hedge or fence!