Types of neglected hedge

Neglect or poor management practices can result in various hedgerow types, which can be readily seen in most parts of the countryside.

Overgrown

This type of hedge is wide spreading and overgrown, but has few gaps. As a wildlife habitat and landscape feature it has high value, but it will eventually deteriorate as there is no new young growth from the base. The hedge will need ‘siding up’ (see below), to bring it back into a condition for laying. Work on this type of hedge is the most likely hedging work to be misunderstood by members of the public, and publicity is needed if the hedge is within public view.

Overgrown and gappy

Many hedges have been allowed to grow up above the height of about 12’ (3.6m), the maximum height for easy laying. The stems or trunks are mostly larger in diameter than the optimum of 2-4” (50-100mm), and are often much bigger than this. There may be large, gnarled stools, caused by the hedge being cut too high, or misshapen trunks which will be difficult to lay. The shrubs or trees may be mature and beyond the age where they easily resprout from the base. Compaction of the ground by machines and stock, and root damage may have further weakened the vigour of the hedge shrubs.

Possible restoration techniques include the following. These are discussed further here. Where there is grazing pressure, the hedge will need fencing whichever technique is used.

1. Laying may be possible if there are sufficient suitable stems, but you will encounter many of the difficulties detailed later in this chapter. There is unlikely to be sufficient material to make a continuous laid hedge of living pleachers, and its function as a stock barrier or shelter feature is likely to be limited, so laying may not be worth attempting. Any gaps may be difficult to successfully replant.
2. Coppicing is less stressful for the tree than laying (see p62), so it may be best to coppice, and plant up the gaps.
3. Oak and ash up to about 30 years of age can be successfully coppiced or laid, but if the trees are older than this, the remnant hedge should be treated as a line of trees (see below).
4. It may be worth simply fencing the remnant hedge, and seeing what comes up.
5. Where space allows, the remnant hedge could be turned into a woodland corridor.

Trimmed too hard

Another familiar hedge type is that of the ‘sheep on spindly legs’ or ‘mushrooms’, where the hedge has been repeatedly trimmed for many years, and has become completely bare at the base. This is made worse by the use of herbicides to control weeds, a self-defeating operation. Trampling by stock, or the closeness of cultivation leaving no field margin also further damages and depletes the base of the hedge, allowing no new growth to come up. Repeated trimming at the same height creates a ‘birds’ nest’ effect, most noticeable in winter, where there are pronounced clusters of twiggy growth near the top of the hedge, stimulated by repeated cutting. The landscape, wildlife and agricultural value of such a hedge is virtually nil.

Possible restoration techniques are:

1. Plant the gaps, then leave the old and new to grow up for a few years before laying and fencing.
2. Where space allows, develop the remnant hedgerow into a woodland corridor.
3. Many of these hedges are those which divide arable fields in the same ownership, and which may not have even an accompanying fence, ditch or bank to provide some refuge from cultivation or herbicide. Where the hedge shrubs have little genetic or wildlife value, much the quickest restoration technique is to grub up the remnant hedge and plant a new one. Choose a line a yard or so off the old line if possible, so the new hedge is planted in fresh soil. If the old hedge has some wildlife or shelter value, you may be able to plant the new hedge alongside, and then grub up the old one a couple of years later, giving time for some plant and animal species to move into the new hedge from the old.

Gappy

Both the above types usually have large gaps, either bare of growth where sprayed or trampled, or with rough grasses, brambles and other non-shrubby growth. These gaps have formed due to the death of hedgerow shrubs, from old age or repeated trimming. Stock or people forcing their way through a small gap may make it larger. Once the hedge shrubs are lost, there is then no protection from grazing and trampling to allow new growth to come up.

Gaps will need filling by one of the following techniques:

1. Laying. Only suitable for small gaps, and does not guarantee new growth at ground level in the gap.
2. Laying pleachers to root, called ‘layering’.
3. Replanting with young hedge plants.
4. Fencing to encourage natural regeneration.

Hedgerow trees

An intermittent line of hedgerow trees, such as ash or oak, may be the only remaining sign of a hedgerow. The smaller hedgerow shrubs of hawthorn, blackthorn, hazel, holly and so on have completely disappeared due to neglect or removal, and only the large mature broadleaved trees remain. Sometimes these trees still show the signs of laying from decades back, with broad horizontal trunks at hedge height. The trees themselves have wildlife and landscape value, but their days are numbered, and unless there is positive replanting and protection, even this last remnant will disappear. Some of the trees may be suffering from die back, due to compaction and cultivation causing damage to the roots.

It won’t be possible to successfully replant a hedge along the line of the trees. Crown lifting will increase the light beneath, but at best replanting will only result in some intermittent sections of hedge divided by trees and gaps. Laying will be a problem, because of these gaps. A better solution may be to retain the feature as a line of trees, by planting young trees as replacements, and felling the mature ones if they become dangerous. Either fence the line, or protect each young tree individually as necessary. If possible, plant a new hedge somewhere in the vicinity, to replace the feature and habitat that has been lost.

Dominated by species unsuitable for laying

Some hedges become dominated by elder or bramble, which are of great value for wildlife, but unsuitable for laying. Elder is very brittle and rather sparse in growth, and does not make a good shelter or barrier shrub. Elder and bramble both survive heavy trimming, and elder forms a large, gnarled stool if coppiced or pollarded. If a traditional laid hedge is the aim, elder should be grubbed out and the gaps replanted. Bramble gives good shelter, and is an effective barrier against people, but is not proof against stock. Cattle will simply push through, and sheep become rapidly entangled. Bramble can be kept in a trimmed hedge, but should be pulled out at laying and any resulting gaps replanted. Elder and bramble are present in many old hedges, and are not a problem if not allowed to dominate. Elder and bramble are valuable species in a wildlife hedge or woodland corridor.