Look at the general conditions of soil, light, shade, exposure and soil compaction. Any of these may contribute to the poor condition of the hedge. There is no point in trying to restore a hedge if the ground beneath is going to remain very compacted from trampling, or if the hedgerow is now heavily shaded by woodland to the south. Shelter may also be important. In exposed areas with few remaining hedgerows or woods to slow the wind, trying to re-establish a hedgerow may be difficult. Artificial shelter can be used for the first few seasons.
Siding up or ribbing
This is needed to bring a wide-spreading overgrown hedge into a suitable state for laying. The work should be done in March or April if the situation is exposed, or otherwise any time during the winter except in frosty weather. Cut up each side of the hedge to within 6” (150mm) of the main stems, and top the main stems at about 12’ (3.6m). This can be done by a contractor using a tractor-mounted flail. Then leave the hedge for one or two years before laying. This time interval is to allow the shrubs to recover from the shock of heavy pruning, and put out some new young upright growth.
Many of the individual hedge shrubs are likely to need special care in laying, and various techniques which can be used in order to lay old and misshapen stems are described later in the chapter.
Coppicing
This is the quickest way of rejuvenating the hedge shrubs, although it appears very drastic. As discussed above, if a shrub won’t survive coppicing, it won’t survive laying, so although it seems a high risk strategy, it is no riskier than trying to lay, and a lot quicker and easier. The only possible advantage of trying to lay the pleachers is if the hedge is in an exposed position, where the pleachers will give shelter to the regrowth. If this is the case, the severed cuttings can be left as a sheltering ‘dead hedge’ on the windward side of the stools, and cleared away the following summer. This strategy is probably anathema to the craftsman hedgelayer, but it can be quickly done by a contractor or farmer with a chain saw, and a tractor or skid steer loader.
The amount of replanting needed will depend on the vigour of the stools, and the ground conditions along the base of the hedge line. In many situations, coppicing will stimulate not just growth from the stools, but the ground disturbance of the coppicing operation and the increased light levels will stimulate growth all along the hedge line. In other situations, or where the coppiced hedge shrubs are of doubtful vigour, regrowth and new growth may be poor.
Planting up of gaps can be done at the same time as coppicing, and if there is a need to do the project in one season and then fence, this may be the best option. If however you can wait and see what survives and what new growth comes up, and take action the following season, this is another option. Stools that fail to regrow can be quickly grubbed up by machine if the hedge line has not been fenced, and replanting in the cleared gaps is then likely to be successful.
Gaps
Gaps in hedges need filling by encouraging growth at ground level. During laying, small gaps can be filled by laying live or deadwood pleachers, to maintain the continuity of the hedge, and provide shelter for new shoots to come up.
If the hedge is alongside a grazed field, simply fencing the gap may allow shoots to grow from suckering species such as elm or blackthorn, or from seeds in the ground. If the land is arable, herbicide use or trimming may be preventing natural regeneration. A severely trimmed hawthorn hedge which produces few berries has little chance of natural regeneration, even if there is no grazing pressure.
Planting small gaps is not easy, because the ground is full of roots. Note that cultivation by farm machinery near to a hedge encourages it to produce roots than run along the hedge line. This actually helps suckering species such as elm and blackthorn to resprout along the hedgeline, but for other species, the roots make it difficult to establish new plants. Hedgelines, particularly those on banks, often also contain a lot of stones and buried rubbish of various types, making planting awkward.
Planting up gaps where the hedgerow shrubs are effectively trees is even more difficult, as the new plants are also competing for light as well as root space and moisture. No new plants will thrive in the shade of the tree, and the ground within the root zone or ‘drip line’ will be drier than the surrounds.
Hedgerow shrubs, such as hawthorn and blackthorn, which have effectively become trees, can be coppiced. Broadleaved forest trees in the hedgerow, such as oak, elm, ash or similar can be crown-lifted in order to improve the conditions for re-establishing a hedge beneath. Remove the lower branches of the tree up to about 20-25’ (6-7.5m). This should be done by suitably trained persons, as working from a ladder to lop branches is potentially hazardous. Wait for a season before replanting, as some hedgerow shrubs may regenerate from seed in the improved light conditions.
Prepare the ground in hedge gaps for replanting by digging over, and removing roots and large stones. If possible, new soil, well rotted manure or compost should be added, to try and get the new plants off to a good start. It is said that new hawthorn plants do not take well if the gap was previously hawthorn, but that holly or blackthorn will establish more successfully. What is certain is that all new plants must be weeded for the first few years to ensure they establish. See here for details of planting.
Fencing
Fencing a neglected hedge against grazing, and stopping any herbicide treatment, will encourage natural regeneration. This is likely to become dominated by aggressive species such as bramble, blackthorn and elder, which although valuable for wildlife and giving some shelter, will not form a hedge suitable for laying and trimming. Such a hedge can however be stock and people proof, with annual trimming to keep it from spreading.
