Hedge management options
Both the Great British Hedgerow survey and the Healthy Hedgerows rapid assessment surveys produce management options suited to each hedgerow surveyed. The information below briefly explains these best practice management options, and points you in the right direction for further information or contacts.
Cutting is an important part of most hedge management plans, and can help extend the time between laying/coppicing. It can also help create the dense thick hedgerows enjoyed by nesting birds and sheltering mammals. However, cutting needs to take into account the need of a hedge to progress through its lifecycle if it is to avoid decline.
When cut to the same height repeatedly, the structure of a hedge will begin to decline. It may develop scar tissue at the trim line, which we call a ‘knuckle’ after its knobbly appearance. This tends to be the point where much of the re-growth will shoot from each spring, to the detriment of the hedge structure over time.
To avoid this, we recommend incremental cutting. When you cut a hedge slightly higher and slightly wider at every cut, even if this is just 10cm, you can avoid this structural damage. Hedges that are allowed to steadily grow in this way maintain their thick dense structure, but have the additional bonus of always providing blossom and fruit. Hedgerow species flower and fruit on second year wood, so hedges cut incrementally taller and wider will always have flowering wood, even in years when they have been cut.
For how long can you realistically increase the size of a hedge?
- If cutting every 3 years, it will take 30 years for a hedge in this cutting regimen to get 1m taller.
- If cutting every 2 years, it will take 20 years to gain 1m in height.
- Even if cutting every year, it will take a decade before the hedge has gained 1m in height.
Of course a hedge cut in this way will at some point need a change in management. After this incremental increase, a hedge can be put into a period of non-intervention, it can be re-shaped, or it can be rejuvenated by laying or coppicing. If a hedge has already declined in structure so that the base is thin of woody growth, it may be wise to rejuvenate it through laying or coppicing first, as incremental trimming will not fix existing issues at the base of your hedge.
Incidentally, this management is no new practice. When hedges were cut by hand, the woodier, older end of the years growth would be tougher to cut through than the younger sappier growth, and would oft be left. Hence hedges would slowly get bigger and bigger until they were left to let up before laying.
Hedgerow species flower and fruit on second year wood, which means hedges cut every year do not provide these vital food sources for our pollinators, birds mammals and insects. We recommend cutting a hedge every 2 or preferably 3 years. If you cut every 2 years, it is important to do so as late in the cutting season as possible. The hedge will have flowered in the second year, but if it were to be cut in September or October, the first crop of berries would be removed and unavailable for wildlife through winter.
Cutting on longer rotations can also reduce the length of hedge you need to cut in any one year. If you have a 2 year cutting rotation, you only need to cut ½ of your hedges each year, if a 3 year rotation you may only need to cut 1/3. Cutting on rotation like this means there will always be hedgerows on the farm at the right stage to flower. Of course, the longer a hedge is left, the larger the material you need to cut through at the end of this period. It is worth ensuring you have sharp cutting equipment which it suitable for cutting growth of this age.
Where space allows, it is good to let your hedge relax into a period of non-intervention where you do not trim at all. These hedges will take a number of years producing flowers, fruit, sequestering carbon and providing fantastic habitat. This can be followed by laying, coppicing or reshaping. When rejuvenated in any of these ways, hedges that have seen a good period of non-intervention can generate a good amount of wood fuel.
It is worth noting that a hedge containing English elm may not be suitable to leave in a non intervention period for too long, as this can increase teh risk of the elm stems reaching a size that makes them more vulnerable to Dutch elm disease.
Hedge laying is a form of hedge rejuvenation suitable for hedges that are thinning at the base, getting leggy or thinning on stems. Hedge stems are cut almost through, bent over and secured. Not only do the cut stems continue to grow, but new shoots spring from the low cut, thickening the base of the hedge.
There are many different styles of hedge laying around the country, some involving stakes and binders, others securing with crooks. Please see the National Hedge Laying Society website for more information.
All hedges need rejuvenating at periodic points in their life. It is rejuvenation practices like laying that enable hedgerows to be such long lived features in the countryside. From generation to generation, farmer to farmer through the many centuries, hedge laying has reset the lifecycle for each hedge, ensuring further decades of use. Most of our hedgerows are old, many of them ancient, and this chain of care and rejuvenation is the reason they still exist today.
Laying mature hedges
Laying is a traditional way of managing hedges when they become over-mature, leggy or beginning to thin. It is worth checking the stems of any mature hedge before laying to ensure that they are not too thick or rotten.
- Creates an immediately stock proof barrier
- Helps to fill small hedge gaps
- Promotes growth from the base, thickening up hedges that have thinned at the base and got leggy
- Be sure to leave the hedge standard trees standing, (those that were trees before the rest of the hedge grew up) and also consider recruiting some suitable new hedge trees where they can be accommodated
- Laying a mature hedge is a good time to plant up any gaps that won’t be filled by the lay
Once layed, we recommend the new growth of the hedge is cut more frequently in the first 5 years, allowing the hedge to gain in height and width with each cut. This will help create the thick branched structure of healthy dense hedge.
Laying young hedges
Young hedges are often planted with about 5 whips per meter, and protected from grazing damage in their early years by plastic tubes. Being layed in their early years (about 7-10 years after planting) can help create a thick, robust hedge. Laying:
- Increases the stem density of a young hedge, as several shoots regrow from the base cut
- Allows the hedge to generate branching from the base of the hedge, which may have become bare from the use of tree protection tubes
- Ensures your young hedge is stock proof
- Laying a young hedge can be easier and cheaper than laying a mature hedge, and will set it up well to become a thick, healthy hedgerow.
- Once layed, we recommend the new growth of the hedge is cut more frequently in the first 5 years, allowing the hedge to gain in height and width with each cut. This will help create the thick branched structure of healthy dense hedge.
If you are looking to rejuvenate a hedge erring on the over-trimmed side of the spectrum, it may be too short to lay immediately. Letting the hedge grow up for a few years will give you the height you need to lay. It is fine to trim the sides in this time if required.
Hedge coppicing is method of rejuvenating a hedgerow. Cutting a hedge at the base may seem like a drastic measure, but from each cut stump several new shoots will grow and so it will have the effect of thickening the hedge back up from the ground up.
Coppicing is suitable over-stood hedges in need of rejuvenation, as well as over-trimmed hedges in need of rejuvenation.
Coppicing an over-stood hedge
Hedges that have become tall, leggy and can lose the density of scrub at the base, which will affect its value for wildlife as well as how well it provides a good stock proof barrier. At this point, a hedge can also lose its stem density. Over-stood hedges like this can often be layed, but sometimes when the stems have got too thick, there is too much rot at the base, or they are too tall or top heavy to safely lay, coppicing is a better option.
- Be sure to leave the hedge standard trees standing, (those that were trees before the rest of the hedge grew up) and also consider recruiting some suitable new hedge trees where they can be accommodated.
- If you are planning on coppicing an over-stood hedge, you must first be confident that it will regrow.
- Make sure you protect the regrowth from being browsed, either with some of the cut brash or through fencing. If regrowth is grazed, the hedge may perish altogether.
- Coppicing is a great time to plant up any gaps, or areas that are thinning in stem density, as the young whips will not be hampered by shading from the surrounding hedge. This gapping up can be a great opportunity to increase the number of woody species in the hedge.
- Do not coppice more than 5% of hedges on your land in any one year. While an over-stood hedge needs rejuvenating for its own long term survival, it’s worth remembering that it will be a big loss of blossom, berries and nesting opportunity, so should be done over time.
- Coppicing is a winter task, and should be done when the hedge is dormant.
Coppicing and over-trimmed hedge
Hedges that have been on the same trimming regimen for too long will also lose the density of branches at their base, developing a mushroom shape and knuckle of growth at the top and leaving leggy, empty bottoms. Hedges that have spent too long in this trimming regiment will have lost stem density; in some places the remaining hedge plants will stretch to cover the losses, but the longer this goes on, the more likely gaps are to develop. When there are too many gaps, when the remaining stems are too gnarled and rotten at the bottom, coppicing is your best bet for rejuvenation
- Make sure you protect the regrowth from being browsed, either with some of the cut brash or through fencing. If regrowth is grazed, the hedge may perish altogether
- This is a great time to plant up any gaps, or areas that are thinning in stem density. This gapping up can be a great opportunity to increase the number of woody species in the hedge.
- Be sure to leave the hedge standard trees standing, and also consider recruiting/planting some suitable new hedge trees where they can be accommodated.
- Coppicing is a winter task, and should be done when the hedge is dormant.
If a hedge has outgrown the space that it can feasibly occupy, (perhaps if you have been incrementally trimming) then as long as the base of the hedge hasn’t deteriorated, it can be reshaped with circular saw attachment back down to a smaller size, from which you can begin incrementally trimming again. This approach can work as long as the base of the hedge hasn’t already shown signs of thinning, at which point the hedge ought to be layed or coppiced to rejuvenate it instead.
Gaps in hedges are often a sign that your hedge needs a change in management. Small gaps can occasionally be filled by hedge laying, but larger gaps, or gaps in a hedge not ready for laying can be re-planted.
- A hedge gap can be a really good opportunity to plant a new hedgerow tree
- Gapping up a hedge can also be a great opportunity to increase the range of woody species in a hedge
- Remove tree guards when the plants have established
A recently planted hedge has two main management options in the early years;
- Leave it to grow untrimmed, and lay within the first 10 years. Laying a young hedge will thicken it at the base and create a stock-proof, thick hedge.
- Alternatively, trim your young hedge each winter slightly higher and wider at each cut. Gradually allowing the hedge to increase in size in this way will encourage it to branch and thicken to produce a dense structure. Care should be taken with this option, especially as the protective tree guards on a young hedge can leave the lower part of the hedge devoid of branches.
Do we need plastic spiral guards? Despite the environmental benefits of trees themselves, some aspects of tree planting can have negative environmental impacts such as using plastic tree protection. The Tree Council has recently launched a Handy guide on tree protection measures to help you make the best choice for your planting project. Rather than being the default position, using tree protection should be an informed, well-considered choice, justified by circumstances at each planting site and the species being planted.
Once you have surveyed your hedges and received management advice for each, like pieces of a jigsaw these need to be put together to form the bigger picture. For advice about how to incorporate individual hedge management options into a farm scale management plan, please see our page on creating a farm scale hedge management plan