Devon field boundaries: restoration standards for agri-environment schemes (TIN039)

Hedge restoration

It is not desirable to lay or coppice every overgrown hedge on the holding. As a guide, approximately 10% of the hedges, spread across the holding, should be laid or coppiced in any one year. This is to create a patchwork effect, with hedges of different age structures at different stages of the management cycle. This approach will safeguard against losses of wildlife habitat or shelter for livestock within a concentrated area.

Good hedge restoration should aim to achieve a complete rejuvenation of the hedge by a combination of hedge laying and/or coppicing and gapping up with new plants. The end result should be a thick hedge, which is free from gaps and has the potential to reach stockproof condition with a five year period.

It is vital that the hedge planting element of a restoration project, (even if only gapping up) is not forgotten. This can be the difference between a successful or an unsuccessful restoration project.

In situations where a hedge bank has not been managed for many years, restoration may take longer than one season. For example a severely eroded bank will need considerable amounts of new soil to return it to its original height. In this situation not all of the coppiced stools or laid material will grow again and new hedge plants must be planted in the following autumn to replace any loss of hedge.

Ideally the majority of hedges should be traditionally managed after restoration, allowing the tops to grow up in readiness for laying, trimming the sides when necessary. This will not be practical for all hedges. Some will be managed by more regular trimming, for example roadside hedges. Please see the hedge trimming section for guidance on sympathetic trimming.

It is advisable to trim newly laid or coppiced hedges hard within the first two years after restoration. The timing of this will depend upon the species composition of the hedge and how fast it grows. Trimming hard will ensure that the plants thicken up in the base, before growing up again in readiness for laying or coppicing.

Unless otherwise agreed in writing with your local adviser, newly restored hedges should be protected by fencing close to the base of the bank to prevent livestock from nibbling the new shoots.

Hedge coppicing

Coppicing is generally undertaken when a hedge stem is too thick to lay, when stems are too infrequent to lay or when regeneration of an outgrown hedge is required. Work should be carried out between mid November and mid March when the hedge is dormant, and before the sap begins to rise. It should be completed before the bird nesting season, generally early March to end of July.

Before coppicing all old fencing or wire should be removed. The stems should then be cut down to between 7.5 and 15 cm (3'' and 6'') from the top of the bank to encourage vigorous re-growth from the base of the plant. Angle the cuts so that water can easily run off.

Note, since holly does not favour being cut down too severely, you will need to coppice it a little higher than specified above, making sure there are several growth nodes left uncut to prevent die-back. Mature beech does not coppice well either , and it will die if too much wood is cut. You should leave one growing beech stem in each stump to help keep the root alive and ensure that new shoots emerge.

Cut material should be removed from the immediate site and disposed of by burning or chipping. This should be carried out so as not to cause any environmental damage.

If coppicing is undertaken in conjunction with bank restoration, you should avoid smothering the coppiced stools with earth by coppicing the stems at the proposed height of the finished bank. This will ensure that the hedge has enough light to grow. If this is not feasible, as so much new earth was required to build up a severely eroded bank, then a new hedge will have to be planted.

Hedge laying

Hedge laying is a method of regenerating an outgrown or gappy hedge and returning it to a stockproof condition. Selected stems (steepers) are partially cut to the base, laid along the top of the bank and secured in position, ideally with a wooden crook. The crooks are set at an angle inwards with the leg towards the centre of the hedge, so that livestock cannot hook them out (as shown in figure 15). The steepers will remain alive and send out new shoots, which will thicken to create new hedge growth. Where appropriate, local styles should be adopted.

Before laying, any old fencing or wire should be removed. Stems that are not being retained as hedge trees and are too big to lay, and any other unwanted growth, should be coppiced before you begin. Retain as many stems as possible. If major bank restoration is to be carried out it should be done at this stage, before the hedge is laid. This will ensure that the steepers are laid along the top of a level bank, and that laid material does not get buried beneath a volume of earth.

Figure 15 Cut steeper laid along top of bank and (below) position of crook to hold down steepers

Figure 16 Good example of a laid hedge

If the hedge is to be cast up, and is wide enough, you can lay steepers in two rows along the top of the bank, so that the cast up material can be placed in between them on the crown of the bank. All material should be laid in the same direction if possible. Where the hedge runs upwards, lay uphill: where the hedge is level, lay towards the south.

Usually steepers will be less than 10 cm (4 inches) in diameter at the base, and 2.5 - 3.5 m (8 – 12 ft) in height. Small saplings should be cut about 5 cm (2 inches) above bank level, and larger ones about 15 cm (6 inches). Trim the cut stub at an angle away from the steeper. Regrowth will be more successful from a clean cut, low stump.

Hedges are normally laid on an 8 - 15 year rotation, depending on the location of the hedge and its species composition. Laying should be carried out between mid-November and mid March when the hedge is dormant and before the sap begins to rise. It should be completed before the bird nesting season, generally early March to end of July. However, you need to bear in mind, that in milder winters birds may be nesting earlier.

The best species for laying are blackthorn, hawthorn, beech, hornbeam, hazel and holly (brittle) but in the absence of the more suitable species, oak, field maple, spindle, elm, willow and even dog rose will lay quite well.

All cut branches should be removed from the immediate site and disposed of by burning or chipping. This operation should only be carried out where there will be no environmental damage.

Gapping up

It is important to remember that the standard payment rate for hedge restoration includes gapping up.
Any gaps in restored hedges should be replanted to ensure the continuity of the hedge. The extent to which you will need to replant will depend upon the successful regrowth of laid or coppiced material.

Planting up gaps can be done in the same season as coppicing or laying, particularly on sparser hedges where there is little potential for regrowth. On denser hedges it may be worth waiting to see what new growth appears, and plant any bare patches the following season. The disadvantage of waiting is that with the increased light levels, created by laying/coppicing, there is likely to be vigorous plant growth on the bank making it more difficult to plant up. When a bank has been restored it is recommended that you wait for at least a year to allow the earth to settle before planting.

For the timing of planting and choice of species, please see the section below on Hedge Planting.

Hedgerow trees

Hedgerow trees are important features in many landscapes. They also provide shelter for livestock and valuable wildlife habitat. They have been steadily disappearing from the Devon landscape over recent years partly due to disease (eg Dutch elm disease), old age, field amalgamation, and the practice of flail trimming hedges, which reduces the potential for saplings to mature into hedgerow trees. Where they are a feature in the surrounding landscape existing trees should be safeguarded and new hedgerow trees should be established for the future.

Figure 17 Hedgerow tree

During hedge restoration all healthy standard hedgerow trees should be retained. Where there are no trees present, or in recently planted hedges that are to be trimmed in future, either select promising specimens and leave them to mature or plant a few trees at random in the hedge. These saplings should be clearly marked or planted in tubes, to avoid damage during hedge trimming. Machine operators need to be given clear instructions to avoid marked saplings.

Saplings should be planted at irregular spacings as hedgerow trees or as clumps of trees, particularly in field corners. Regularly spaced hedgerow trees look unnatural in the landscape. Trees can also be planted at the foot of the bank in field corners, where they will not get in the way of the hedge trimmer. Avoid establishing trees where there are overhead cables or risks to road safety.

Many native broadleaved tree species are suitable for maturing into standard hedgerow trees, depending on soil and environmental conditions

Oak is one of the most common hedgerow trees and holds the highest wildlife value. Slow growing, long lived and deep rooted, it helps to stabilise the hedge bank. It casts dense shade for livestock shelter.

Ash is quick growing and casts only a light shade. It is not a good shelter tree. It thrives in deep well drained loams.

Beech favours good drainage and can withstand exposure. It casts a heavy shade and only Beech and Holly will survive in the hedge beneath it. Plant this species only where it is locally characteristic.

Hawthorn matures into a lovely standard tree, high in landscape and wildlife value.

Holly casts a heavy shade and should only be encouraged to establish as a tree where it is growing in the hedge beneath.

Crab apple will make a successful standard hedgerow tree.

Whitebeam, and Wild Service Tree will grow well on chalk and limestone.

Rowan is useful in more exposed upland areas on acid soils.

Sycamore is tolerant of exposed conditions and salt spray.

Field maple thrives on well drained lowland soils and casts only light shade.

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