How to Rewild

Hedgerows

Habitat Management Plan

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Hedgerows
Habitat Guide

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Hedgerows are not just a collection of individual shrubs, but also a linear feature, which makes them valuable for weaving together our landscape. We have lots of fragmented patches of nature in Britain, and hedges act like a highway system that connect these up across inhospitable Built-up Areas & Gardens, Modified Grassland, Arable & Horticulture. But beyond these benefits, hedges are also a useful boundary and screen, keeping livestock and people in or out, while allowing wild animals to pass through, unlike a fence or wall.

The best type of hedgerows for wildlife, like any habitat, are native and diverse, both in terms of species and structure. Like woodland, hedges can contain every layer of vegetation, from ground flora up to high canopy (‘emergent trees’), with shrubs, climbers and small trees filling in the gaps. Planting a hedge is not only easy, but often relatively cheap due to grant funding and volunteer labour, and extremely effective at boosting biodiversity on your land.

In degraded ecosystems, even non-native hedgerows can play a useful role for refuge and dispersal. But hedges are not a wild habitat – they are a human invention, and the closest thing we have to them in nature is Dense Scrub. Wilder hedges with variable edges and height mimic the structure of this scrub habitat, benefitting from its high biodiversity.

Sub Habitats

Linear scrub with more than 80% cover of native woody plant species.

Linear scrub with less than 80% cover of native woody plant species.

Value

Hedgerows provide a wide range of different services for wildlife and humans. For humans and our livestock, they are a better windbreak than fences, creating a visual barrier that doubles as a security system (especially thorny hedges). For animals, the benefits go even further:

  • refuge from predation and weather
  • nesting and roosting opportunities
  • fruit, nuts, nectar and leaves to eat
  • lookout post
  • hunting spot
  • ambush opportunity
  • twigs and leaves for nesting material
  • landmark for navigation (especially for bats)

 

With all these benefits, it’s no surprise that Native Hedgerow is a Priority Habitat under the UK Biodiversity Action Plan. While hedgerows are inherently artificial, they carry much of the benefits and biodiversity of scrub (the wild equivalent of a hedge), with the additional benefit of connection across the landscape.

While most hedgerows were first created around the time of the Enclosure Acts (from about the 1750s onward), they have existed for many centuries longer than this. Landscapes which are characterised by hedge-lined fields are described as ‘bocage’ and they are more common in some parts of the UK than others. When it comes to hedgerows, heritage is part of the value – protecting the traditional form of the landscape as seen from a distance. On the flat alluvial soils of East Anglia, drainage ditches tend to be the typical boundary of large arable fields, but in the rolling Westcountry, hedges are a standard feature in smaller pastures.

The species growing in these hedgerows also varies depending on the location, soil type, exposure, deer population and traditions, even within a few square miles. Preserving the traditional, local species mix is not just valuable for heritage, but also tends to create higher biodiversity, as local species of animal will be better-adapted to the hedge plants.

Common Whitethroat
Dense hedgerows provide nesting and foraging opportunities for a huge range of organisms, including birds like this Whitethroat.

Protect

Because linearity is key to a hedgerow’s value, removal of any part of a hedge will obviously damage its potential for biodiversity. Removal or destruction of ‘important’ hedgerows is also restricted by The Hedgerow Regulations 1997, which covers everything from ancient hedges to long hedges and those containing protected species. Animals travelling along the system might not cross open grassland or an artificial surface, where they will be exposed to predators. So, when changing access, it’s better to widen an existing gap than to create a new one – if this is permitted.

Hedgecutting is regulated, to protect nesting birds from disturbance during the breeding season. It is an offence to intentionally damage, destroy or take the nest of any wild bird while it is in use or being built. While the bird breeding season is not recognised in law, this is widely interpreted as running from 1 March to 31 July. There are exceptions to the hedgecutting dates above, if:

  • the hedgerow overhangs a highway, road or footpath over which there is a public or private right of way and the overhanging hedgerow obstructs the passage of, or is a danger to, vehicles, pedestrians or horse riders;
  • the hedgerow is dead, diseased, damaged or insecurely rooted and is likely to cause danger by falling on to a highway, road or footpath; or obstructs the view of drivers or the light from a public lamp;
  • to carry out hedge-laying or coppicing during the period 1 March to 30 April (inclusive)
  • to trim a newly laid hedgerow by hand, within 6 months of it being laid; 

 

Keeping a hedge healthy does require a bit of maintenance. Flailing is the typical method for maintaining ‘tidy’ hedgerows, and this involves a tractor-mounted hedge trimmer, which may be a necessity on larger projects. Regular cutting can recreate the effects of herbivore browsing, generating fresh vegetation growth, which increases the diversity of invertebrates. However, flailing does not need to occur as frequently as is typically prescribed (once/year), and doing it less often could result in more flowers, more emergent trees, and more wind protection for livestock. 

Any hedge needs maintenance in the long term if it is to function as a boundary, and there are systems which may be more appealing on conservation projects. Hedge-laying is an alternative to flailing that takes much more effort but results in denser hedges – stems are partly cut, then laid sideways in a tight line. Coppicing is an option which removes the plants completely every few years – cutting them back to near ground level, after which they grow densely upwards. Browsers, such as cattle, may maintain a hedgerow by nibbling it, but the action is inconsistent and irregular, so it is hard to use this for boundary maintenance.

If hedgecutting is stopped entirely after a long period of flailing, it can result in top-heavy growth of scrub with an open base. This structure is not only poor as a boundary but is also likely to topple sideways in the wind. Laying or coppicing the hedge one section at a time (over a few years), while allowing natural regeneration of scrub alongside it, will create a wedge-shaped regrowth pattern that shouldn’t collapse.

Hedgerows amongst pasture
Emergent hedgerow trees like the Ash popping out of these hedges, provide shade and wind protection for livestock.

Restore

In degraded open landscapes like gardens and fields, we can significantly improve diversity by planting new hedges. Happily, there is funding available for hedgerow planting – if you plant 100m or more of shrub in a single run, which connects two woodlands (even via another hedge). If you’re not eligible for this funding, then you can still buy discounted packs of hedge mixes from the Woodland Trust directly.

You can still then benefit from adding on a few additional species found in your area (particularly from seed/cuttings), as these packs are fairly low in diversity. You can browse tree species (including many shrubs) by their suitability for hedgerows in our Tree List – but don’t forget smaller shrubs like Butcher’s Broom and climbers like Dog Rose. The best way to find which species to plant is by walking up and down healthy local hedgerows with a Plant ID app (or a botanist!). Tube protection will again increase your costs, but may be essential, depending on the herbivores and livestock on your land.

In the farmed landscape, hedges can improve the yield of livestock, especially when they are managed as ‘shelterbelts’. Animals are sensitive to both cold and heat, and their productivity decreases when they are exposed to these extremes of temperature. High, wedge-shaped hedges are more effective windbreaks, which reduce the impact of windchill, provide protection from driving rain and create shade on hot days. ‘Wedges, not hedges’ is the best way to think about this change in practices, which sacrifices a small amount of field productivity in favour of thicker hedgerows that improve livestock yield and health. There’s more about this in the guide to Cattle.

Subdividing existing fields with new hedges and tree lines is now a common practice, and these can be a mix of fruit-, nut-, timber- and fodder-yielding varieties which add to the productivity of the system. This is referred to as either a shelterbelt (pure hedgerow) or alley cropping (individual trees), but a mix of the two could create both productivity and biodiversity benefits. More details of these systems are provided in the Cattle guide.

In projects where biodiversity is the main priority, and boundaries aren’t important, then hedgerows can be allowed to march outwards and upwards into Dense Scrub and Broadleaved Woodland. The most effective management approach here involves ‘scalloping’ – cutting into the hedge as it thickens out – to reduce the regularity of its edge and improve the structural diversity. This creates sheltered ‘bays’ that can be much warmer or cooler than the surroundings and exposed ‘headlands’, with very different humidity levels, enhancing the biodiversity of the system. 

When laying, coppicing or scalloping a hedge, the cuttings  – ‘brash’ – can be reused on grassland to protect emerging trees, or at the edge of the hedgerow, to mock-up the desired future structure. The brash will be used as a refuge by wildlife, and is an easily visible marker which allows others to see where a hedge or small tree lies, protecting it from walkers, groundskeepers and livestock.

When planting out a hedge, as already mentioned, the priorities should be:

  • Traditional mix suitable for the locality
  • High diversity of plants
  • Trees, shrubs and climbers
  • Tube/spiral protection where required
  • Plants suited to soil type, exposure, drainage etc (use Buy Native)

 

Many hedge plants can be completely coppiced to the base, but if you’re growing emergent trees through the top, these will ideally be spared the cut when flailing, laying or coppicing. During the early stages of development, the Woodland Trust recommends planting emergent trees in extra tall tubes to allow easy identification and permit them to reach above the average hedge height.

How to Plant a Hedge

When planting a hedge, you may have the opportunity to benefit from help in the form of volunteers. However, a team of volunteers is only as good as their leader. They will need clear, specific instructions at the start of the session, suitable tools, and an effective demonstration (ideally an example, too). Otherwise, you may end up with a gappy hedge and plants with roots exposed to the frost. Preparation is key – read up before you start about how to plant a hedge, and print off this guidance, so that attendees know what to expect…

  1. Typical hedges will need about 8 plants per metre – bare root plants are supplied, which slide into spade-depth slots in the soil.
  2. Get the right number of plants in the right places – if 60% are Hawthorn, make sure they’re spread out evenly, rather than 60% of the length being pure Hawthorn.
  3. There is no need to dig a hole – just push in the spade, lever it sideways, and slot in the roots down to the base of the stem.
  4. Remove the spade, and heel in the roots from both sides with your foot to close the gap completely.
  5. Bang in a stake about 5cm from the stem, and slide on your tree shelter, before tightening the cable ties around the stake (if it’s a spiral shelter, ties and stake may not be required).

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