Case Study: Managing hedges on an extended rotation – Using an excavator mounted finger bar and tree shear

Author: Fraser Hugill: Throstle Nest Farm, Sproxton, North Yorkshire

The Management Challenge

In recent years I have taken over the management of the family farm. The farm business consists of 350 acres, split over two different holdings, both with fantastic hedgerow networks that support lots of wildlife but with very different management needs. I wanted to find a way to manage the hedges myself that would be cost-effective and benefit wildlife.

The solution came in the form of digger-mounted finger bar cutter and tree shear. The results have been really good for hedges, wildlife and soil – and have given me the perfect excuse to keep the farm’s best big boy’s toy - the digger.

The two holdings that make up my farm business are Throstle Nest, on the southern edge of the North York Moors, and White House, on the northern edge of the moors. The farm is roughly 50% arable (Winter Wheat, Winter Barley, Spring Beans, Oats) and the remainder a mix of permanent pasture and grass/herbal leys supporting a herd of 50 pedigree Beef Shorthorn suckler cows.

Throstle Nest has a really intact hedgerow network, very similar to 1840s maps, with species-diverse hedges. Prior to our arrival these appeared to have been trimmed annually and were grazed by sheep, but were generally in a good condition. Throstle Nest also has heavy clay soils which are waterlogged throughout winter. This means that using a conventional tractor-mounted flail cutter was only viable in the Autumn as the wheels cause too much damage to the ground in spring.

White House has had very little hedgerow management - Dad pretty much ignored them, which created a good habitat, but hedges were starting to grow out and lacked structural diversity. Although Dad’s management had benefits for wildlife, this management could not go on indefinitely!

Both farms are in Countryside Stewardship with both agreements up for renewal. The current agreements include hedgerow revenue and capital options to gap up and coppice hedges, and these options will be included in the new agreements.

Managing Hedges with Excavator Mounted Equipment

Moving to Throstle Nest in 2012 involved a lot of infrastructure work so we purchased a 5-tonne excavator. The plan was originally to sell it once work was complete, however this prospect was akin to taking away a children’s favourite toy!  So, somehow this had to be justified. But how? By buying more toys to attach to it of course!

The first piece of kit was a Slanetrac 1.8 metre finger bar hedge trimmer which runs off the excavator’s third service. It works as a combine cutter bar using the same blades as our combine. Unlike a tractor-mounted flail, cutting is done in one single pass, so no going backwards and forwards which risks increased damage to the ground.

Cutting involves staying in one position to cut 4-5 metres off the hedge side and then from the top. Then moving another 4-5 metres forward to the next section. This gives excellent control, particularly when cutting larger sections of hedge.

 

Bar hedge trimmer cuts through 3 - 4 yr old hedge wood
Bar hedge trimmer cuts through 3 - 4 yr old hedge wood
Cutting several feet of mature hedge growth in one cut
Cutting several feet of mature hedge growth in one cut
Hedges.IMG_0856

One of the key advantages over a flail is the very pleasing clean neat cut, which is particularly important when managing hedges on an extended rotation.

So often I hear that if you don’t cut your hedges every year you get a “right mess” but the photos below help illustrate how clean the cut can be, and how strong regrowth is behind the cut.

Cost also comes into play, with the finger bar costing £2400 it was, in my view, not overly expensive, albeit our finger bar cutter is a little on the light side for our management objectives, the key is not to be in a rush and to learn the machine’s limitations.

Hedges..IMG_0876
Hedges...IMG_0878

The brash left behind has both advantages and disadvantages, depending on your personal viewpoint. I try to make a single cut so each piece of brash is as large as possible, making it easier to then bulldoze cut material together with the excavator blade and/or the front toothed bucket.

If the ground is very wet, this is often done at a later date, being mindful of breeding birds.  I have been pleasantly surprised how effective this actually is as the material acts as a rake. Note we have no roadside hedges. Touch wood, we have had no issue with thorns, either with cows or tyres as we use the tracked digger to clean up.

An advantage of the long sections of brash is you can actually clean up, compared to a flail which sends material everywhere. We don’t have sheep, but if we did, thorns might be a concern due to sheep’s ability to find danger!

Hedges cut on a 3-4 year rotation generate a lot of material, as the photos illustrate. The tidiest approach is to burn it, however that would be too conventional! As a result, where there are gaps in the hedge, the brash is used to fill them to discourage livestock and people with dogs (picture, left below) or to make habitat piles (picture, right below).

Where ditches are fenced off (our ditches are small and seasonally dry) I tend to leave the brash in situ to provide some dead wood but to also potentially slow flow and to help intercept sediment. Using the material from the hedges adds to the sustainability of our approach.

If I was a workshop tinkerer I would be making a Bailer to somehow get the material into our log biomass boiler!

Hedges.......IMG_3699
Hedges....IMG_3257

The second attachment for the excavator is a TMK tree shear, which again is operated via the third service. This machine basically grabs hold of a tree, branch or shrub pulling it across a cutting blade. The cut off material can then be placed in a pile or wherever the operator wants.  As with the finger bar I try to fill gaps with the material, and section out any timber for logs, but ultimately some of the brash is burnt. This machine has really helped with managing some of the bigger grown-out hedges.

The speed and ease of coppicing it provides is amazing and clearing up the material is so easy as you have hold of it in the comfort of a cab.  A key lesson is to take a long-term approach and not to blitz all the hedges at once just because you have a tree shear and have to get all CS capital works done in 2 years - owning a tree shear should perhaps come with a licence! Manage hedges over your lifetime not on an annual basis.

It should be noted that with larger material the tree shear/ cut is not especially "clean", however this is where compromise sometimes come in. With full coppice we tend to finish off stumps with the chainsaw to limit the ripping effect of the shear (picture below).

I am also playing with part managing grown out hedges through part-coppicing, digger-laying and generally mixing up diversity of management.

Tree shear on Alder

The ultimate sign of success, however, is the species using the hedges. We are perhaps culpable of not doing enough survey work, however the thing we have really noticed is the increase in yellowhammers.

This will not be solely down to hedges as we have winter bird food and supplementary feeding - however the hedges are a key component in the ecological jigsaw.

Yellowhammer Emberiza citrinella, adult male feeding on grain at Hope Farm,  April 2002

Why we take this approach to hedgerow management

Our approach comes down to circumstance and objectives and will not be for everyone.  Our aim is to:

  1. Maximise the ecological value of hedges by allowing flowering for pollinators and fruiting for birds and small mammals by pushing back cutting dates to as late in Feb as possible and extending the cutting cycle to have 75% of hedges in berry and flower production each year.
  2. Have control over hedgerow management, allowing flexible and responsive approach to management based on ground conditions and most importantly what I see while cutting the hedge. This is particularly relevant to hedgerow trees and allows me to first spot them and then not cut them.
  3. Have a diverse range of hedges at different stages of succession from regenerated through planting and coppicing to mature with future hedgerow trees establishing.
  4. Incrementally cut the hedges so they are not cut to the same point, so they expand overtime ultimately leading to being coppiced and the process starting again.
  5. Have hedges that provide shelter, function as a livestock barrier and contribute to the agricultural success of the farm.
  6. Minimise ground disturbance/compaction

The key thing however is mind-set, an uncut hedge to me no longer looks messy, whereas a bonsai flailed hedge looks like a massive missed opportunity. As farmers we tend to hate bare fallow and that’s how I feel about an annually flailed hedge when it is not getting the chance to produce a crop of flowers and/or berries

Hedge to right coming into third year after cutting has comparable flowering with unmanaged hedge to left
Hedge to right coming into third year after cutting has comparable flowering with unmanaged hedge to left
Same hedge close up - note, honeysuckle
Same hedge close up - note, honeysuckle

Sources of further information/ advice

Delivering Championing the Farmed Environment (CFE) events, in my role as Northern Co-ordinator has really helped develop my understanding of hedges over the years.

Events with Steven Falk, an excellent entomologist, have really highlighted the value of hedges and particularly the flowering cycle of hedgerows for pollinators early in the season, before habitats like nectar mixes and meadows come into play.

Hedgelink also produce excellent information about hedgerow management which we have used in events.

Encouragement received from Chris Tomson, who was our local RSPB adviser has also fostered a greater interest and understanding.

Case Study : Bumper crops from hedgerows

Author: Jo Terry
Farm: Upper Hollowfields Farm, Worcestershire

Aims:

Upper Hollowfields is a mixed farm with arable crops and cattle/sheep grazing the grassland areas. The hedgerow pattern contributes to the historic character of the site. Hedge management is considered carefully in each field, where possible complimenting other environmental work on the farm, for example higher, thicker hedges provide sheltered semi-shaded spots on 6m wildflower arable margins to benefit plants and wildlife suited to these conditions.

Our hedges are managed sympathetically to provide the best range of habitats for wildlife including the brown hairstreak butterfly, a variety of bird species and small mammals. We aim to preserve the historic landscape pattern, whilst maintaining hedges as physical barriers to help prevent flooding, wind erosion and pollution. It is important that hedge management results in a plentiful berry crop as a food source for wildlife during the winter months and hedgerow trees are managed sensitively.

Management:

We benefited from advice from Natural England on hedge options, and Butterfly Conservation guided our hedge cutting schedule to suit the brown hairstreak butterfly, the female of which lays eggs on young blackthorn shoots. They stressed the importance of blackthorn coppicing and 3 to 5 yearly cutting rotation for this rare species. Birds have been recorded through the RSPB Volunteer & Farmer Alliance Scheme. Our RSPB volunteer has continued to monitor the birds pointing out the significance of established hedges for yellowhammers, lesser and common whitethroat, chiffchaff and willow warbler all of which breed on the farm.

Hedges have been sympathetically managed to provide a variety of hedge heights to benefit the varying needs of birds species, e.g. hedges over 4m tall for bullfinches compared to 1.5m for whitethroats. Blackthorn suckers have been allowed to grow along field edges to provide young shoots for the brown hairstreak butterfly. Hedges have been coppiced to regenerate the hedges natural cycle of growth. Thinner hedges have been replanted with native species including blackthorn. Hedges have been cut on rotation, sometimes only cut on one side to allow maximum benefits for wildlife with many cut once in 3 years. Cutting takes place at the end of the winter season to allow a generous berry crop to benefit wildlife.

During one very dry summer, new hedge plants failed and had to be replanted. Extreme wet weather conditions on another occasion made hedge cutting difficult, so some hedges were cut a year later. Cutting on a 3 year cycle made hedges more difficult to cut, so we sought the use of a hedge cutting contractor with equipment appropriate to deal with larger hedges providing excellent results.

We will continue to monitor wildlife on the farm and allow results to dictate the work, seeking further specialist advice on other species and adapting the work accordingly.

We have found the total hedge cutting cost for one hedge to be roughly the same, if the hedge is cut once a year or once every three years.

Achievements:

The benefits are stronger, thicker and denser hedges with new growth where coppiced. They provide good shelter for stock, a windbreak for crops and compliment our other agri-environment scheme options.

The success is obvious and measurable. West Midlands Butterfly Conservation have recorded over 400 brown hairstreak eggs on hedges to the east of the farm this winter.

82 species of birds have been recorded by our RSPB volunteer. For many of these such as the bullfinch, linnet, song thrush and spotted flycatcher hedgerows are a primary habitat. Berry crops are plentiful due to this management, providing a valuable food source for wildlife. During extreme wet periods, hedges can be seen to contain flooding.

Our tips would be:

- Assess your own farm environment and choose management options that fit with your farming pattern and benefit species relevant to your situation.

- Don't hesitate to seek expert advice from organisations such as the RSPB and Butterfly Conservation to give in-depth understanding of management techniques and their benefits relevant to your farm.

- Choose good quality hedge plants and pay attention to details such as mulching and using rabbit guards when planting.

www.wildhollowfields.co.uk