Hedges and Hurdles in England

History, Construction, and Maintenance
It is accepted by countryside experts that the older the hedgerow the greater variety of species there are likely to be in it. The average number of woody species in a thirty metre stretch can be used to estimate the age of a hedgerow after its initial planting: for every additional shrub species in a hedgerow you can add a further 110 years (Hooper's Law). Hedgerows can contain over twenty-five trees and shrubs although not all in the same area of country. Within this number the most likely present will be: Blackthorn, Cherry plum, Common elm, Elder, Field maple, Hawthorn, Oak, Sycamore, Wayfaring tree, and White beam. In ancient times, Oak was planted during the initial planting - at each corner of a field, as a marker. Spear planting of Hawthorn cuttings generally the favoured basis for most hedge construction – able to be laid later on - although any growth that has thorns proves to be a nuisance.

In England, prior and during the Dark Ages, the division of land into fields began when allotments were made to individuals to facilitate strip farming.The Manor and The Bishop The strips were given, or rented out, depending on the status of the individual - and his importance to the lord of the manor. The hierarchy started with the king who owned the land. He gave some to his henchmen and relatives and they in turn gave some to the church for salvation. This passing down the line was to ensure that a standing army was secured; that was fed, armed and ever-ready. The lowest lord or squire, who could be lord of the manor, also paid rent to the landowner. It was the lord’s job to ensure the land was worked - that the tithes were paid, thereby keeping the whole system working. The lord’s Bailiff and elected Reeve saw to it that it functioned well which it did because it was in everyone’s interest that it did so.

After the Black Death the land began to be developed for a slowly increasing population. By this time the monasteries were becoming an economic force making huge sums of money from the production of wool. After the dissolution of the monasteries their land was distributed to the king’s favourites for their support. They in turn sold it to wealthy individuals, farmers, and existing landowners. The lord of the manor who also benefited parcelled out land to freemen, copyholders and prominent citizens.

During the hundred years 1750 – 1850, a series of Government Acts allowed the purchase of waste land. This was the period of land enclosure instituted to improve the land through better farming methods. As village folk gained wealth through entrepreneurship and hard work they purchased land from the poor, the destitute, and widows. As the existing worked land and newly purchased common land was split and fenced off: ditches were dug, hedges planted, and plots re-parcelled, and exchanged - to increase harvests and profitability… it was the start to High Farming, when the production from the land was carefully considered and planned.

Dry-stone walls and wooden fences were expensive to build; the latter needing an almost continual management programme to keep it stock proof. A hedge is relatively cheap to plant, easy to make stock proof, and can be harvested... Poor hedges and gaps can easily revitalized, rebuilt and renewed. Today we recognise hedges to be conducive to the maintenance of wildlife flora and fauna. It is also welcoming to visual appreciation, stimulating to the human soul and contributes to the landscape. Animals can make the hedge a home, a corridor to the next field, and a sauce of food and security. Both birds and insects can balance the losses to farms and gardens due to aphids. All hedges have a rich variety of grasses, flowers, orchids and fruits. More action is needed from landowners to regenerate, rebuild, renew and replace hedges to counteract global warming.

In all stages of work, to lay a hedge or construct a hurdle, green timber – unseasoned timber, is used. The terms seasoning and drying are synonymous. When seasoned moisture is drawn from the cells the wood shrinks. The moisture content of timber should correspond to the humidity of its surroundings when used. Green timber is less strong than seasoned timber but is easier to cut, split, bend and spring.Tudor House Construction

The newest hedgerows contain hawthorn because of its easy planting, rapid growth and dense low crown. It will stand any amount of lopping and trimming forming a dense interlacing network of twigs which make the hedge almost impenetrable. The trunk is often fluted and of minimum circumference giving little timber for a fair size of tree; thrives best on limy dry loam but will grow on most soils. It is wind-firm, frost hardy and bears a considerable degree of shade. It is long-lived and the wood is tough, strong and durable in the open. Hazel coppice working has almost died out although there is a revival for spar making for thatch makers.

A list of common hedge trees and shrubs
'Hawthorn': goes by the name of May, Whitethorn and Quick thorn and is regarded as the best of all hedging. It belongs to the Rosaceae family, which includes apple, plum, pear and cherry. There are two types Oxyacantha, which has two flower styles and monogyna Jacq. with spikier twigs. They are both so similar as to be described as one. 'Hazel': Corylus Avellana L. of the family Betulaceae, the same family as birch, hornbeam, and alder; also known as Filbert, Cobnut, and Nutwood. As coppiced hazel is the most frequent type of under-wood, the shoots are straight, elastic and flexible, and the wood is frost-hardy. Its gear feature is that it is easily split which makes it ideal for wattle, laths, hurdles, hoops, crates and hedge stakes. 'Willow': Salix, Salicaceae, closely related to poplars. Much used for wattle hurdles and stakes. Cultivated mostly by cuttings. When used as stakes if carefully driven will take root and make a living fence. 'Elder': Sambucus niga L. Family includes honeysuckle and the wayfaring tree… Also known as elderberry. Produces a quick hedge and assumes a bush like form. Cultivated like the willow by cuttings. 'Sweet Chestnut': ''Castanea sativa Mill. Fagaceae.'' All know as Edible Chestnut. A Hardwood which coppices easy on a rotation of 80 – 100 years… more profitable still on a rotation of 7 – 14. The stools cut any times without impairing vigour. The coppices shoots are valuable for split-pale fencing and hop poles. It is similar to oak – used to construct ancient buildings although its downfall is that it splits easily, although slightly lighter in weight and weaker in strength.

Timber Sizes
For square cut or split square, uncut or trimmed, with or without bark (white or brown) the order is: 'Square' Post = 30cm – 10cm (squared diameter), Stake: 15cm – 5cm (squared diameter). 'Round': Pole or Pale = 30cm – 10cm. Stave, or Staff = 15cm – 5cm dia. Rod or Wattle = 5cm – 3cm dia. Stick = 4cm – 2cm dia. Wand, Twig or Switch = 3cm – 1cm dia. Sizes are for guidance only

Hedge Maintenance
It is essential to maintain form, denseness and to fill all gaps; it was during the fifties that the planting and maintenance of hedgerows declined. Fields were linked together to form a more economic size for modern machinery. When these hedges were grubbed up field edges, ponds, ditches, and small corners were included in the new squatted shape. Fields became boggy, footpaths were lost, chemical run-offs occurred and the fine soil clogged what ditches were left. What benefit was felt by animal and man from the windbreaks were lost too. It was forgotten that hedges provide a windbreak twenty-times its height downwind.

Although the countryside became more productive for cereals the wildlife, diversity of plant life and the characteristic landscape suffered. Now there is at last a realization that a more reasonable approach should be made and farmers and land managers given the latitude and grants to replace and rectify past mistakes.

Planting mature cuttings of about 50cm dia planted by artificial regeneration using the spear or slit and heel planting process will provide new and infill hedging. Hawthorn trees for hedging are raised from cuttings should, when planted, be secured against rabbits by a plastic tube. Planting is carried out in the open, if possible, between the middle of November and the middle of April. As a rule, broad-leaf trees in the autumn and conifers in the spring. It is obviously best if the area to be planted is cleared of weeds but this is not essential. However, any climbers should be removed. A new hedge does not require laying. It is more common to plant alternately in rows 50cm apart, 50cm between plants.

If you believe that in the future your hedge will be laid do not plant Hawthorn, Blackthorn, Quick-thorn, Holly, Cotoneaster and Quince, for the thorns will prove to be a menace to cut and pick-up. Better to plant: Chestnut, Beech, Hornbeam, Bush willow, Elder and Robina. This selection will be easily managed, productive and offer an equally good environment for wild life. However, a mixed hedge will always give a greater variety of flowers, foliage, food and habitat. Traditionally Oaks were planted at the corner of each field to indicate ownership and extent…

The Layered Hedge
The aim is to produce a hedge which is approximately 120cm in height by 70cm wide, stock-proof and dense. It may have mature trees growing out of it to give character and variety, but these should be planted close together but to act as shelter and shade, variety and food. Thought must always be given to the eventual growth, suitability of soil, position and whether the hedge has to be immediately stock-proof.

'The Survey': As with all building or farming matters, a survey of the lie of the land is essential. So too, an assessment of ‘the potential of the site’ for growing crops or stock. The access for machinery to till the soil and to cut the hedge as well as to cart away cuttings and crops is paramount.

Once the survey has been completed that you have come to the conclusion that the job can be done the site needs to be cleared by mowing, flailing or cutting. It’s quite useless to stand in a bed of nettles, be attacked by the tendrils of blackberry, or to almost reach the centre of the hedge. It is a guide that you should be able to just reach the other side of the hedge to be. If that cannot be done you may have to partially lay the hedge backhanded - which doubles the amount of work.

Mow up to the hedge on both sides, if possible. Flail or cut to give yourself room to move - to get into the hedge… but do not drastically trim for this only delays recovery. This mainly refers to hedges which have been allowed to almost disintegrate, and form massive clumps of tangled undergrowth - with too many trees.

A hedge which has been properly laid shows (written for a right handed person)the selected stems partially cut through on the right hand side, fairly close to the ground - to about 30cm. Work starts on laying the hedge at the left hand field corner – or to the right of the gate, working anti-clockwise round the field from the front, or face, of the hedge. The front of the hedge is the outside face – the outside of the field to be worked, this generally applies to all hedges, walls and fences. This weakening of the stem by partially cutting through allows the stem to be bent. The plant is forced over to the left – to assume an angle, which is suitable for regrowth, and will fill the hedge. The cut should take account of the thickness of the stem. Do not cut right through, or just leave the bark… that is quite useless.

The object is to allow the plant to be bent over whilst still maintaining plant life – a quantity of tissue directly under the phloem or bast, which is just under the bark. Beneath this is another layer of plant cells called cambium where the new growth originates to feed the plant. Food for growth travels up and down these cells. Two types of cell: one enlarging, and the other dividing, form new tree tissues; the roots absorb water containing mineral salts, which are conducted up the trunk by capillary action to the leaves. The leaves take in from the air carbon dioxide. This chemical together with water manufactures starches and sugars. Photons of light on the leaves part reflected, some transmitted, others absorbed, split water into its constituent parts. This act on the chemical chlorophyll by photosynthesis converts carbon dioxide and water into sugars which gives energy… this food is drawn down the phloem – the cells beneath the bark.

The cut or cleft is made with a chain saw, hedge cutter or small broad-headed axe or billhook. Naturally if using the latter you will be better able to trim, slash, and cut lesser branches and undergrowth. Some homemade hooks, bills and axes have a cast hammerhead in the design others have a crook which is handy to drag branches towards you. Trim the shape of the hedge as you go paying attention to the form of the base, cutting close to the ground all the brambles and briars to form crowns. Haul away any dead wood and rubbish to burn later.

The hedge may offer some of its own stems or stakes to give support and substance whilst you build. These will have been noticed any allotted in the original survey. Some hazel or chestnut coppice stools will give you your stakes and the elder and willow will supply the bonding ties to link the stakes together - at the top. Do not on any account use plastic or wire in any of the tie jobs.

The central stakes are inserted to give form and strength; the hedge layer will need a number of pointed stakes of at least 150cm long by 20 – 10cm in circumference. For good effect these should be placed along the centre of the hedge at 40 – 50cm intervals. Where the hedge is already dense or the ground too rocky or woody these stakes can be omitted. However, if these stakes are not placed into the hedge the strength giving binding at the top – the interweaving willow laid in-and-out of the stakes, cannot be rove, nor the laterals be woven into the structure quite so well.

A well shaped hedge shows a tapering towards the top which gives the hedge strength. The hedge is to act a wind and snow break as well as to act as a shockproof barrier. The taped shape offers space for saplings to grow into trees which is beneficial for wildlife and provides good cover in its dense branches. This is the ideal shape and one which allow for added growth - prompted by light, as the lower buds begin to develop and grow… in addition, when further pruning takes place on an annual basis the shape is maintained.

Hurdles
Other than the more permanent structure of a wall or hedge, to create a boundary that is both shockproof and windproof is the fence. There are a number of different fence designs some more costly than others. However, they all do the same task. Fences are more labour intensive to maintain but are cheaper than a more substantial wall. Within the list of fence types comes the 'hurdle' Larch lap fencing is similar in design. Traditionally hurdles were 100cn high built as a transportable sheep pen. A method used thousands of years ago. Like all traditional crafts they are all closely allied. Hurdles were made the restrain livestock. Wattle was always a part of the house builder’s portfolio to make frame infills, and simple rustic furniture. All the tools used to cut, split, and shape the wood… and then later, to secure the joints, are all similar. Today hurdle making is a woven form of fencing now adopted for rustic garden landscaping.

In times past the construction of a hurdle would have been in the forest glade with all the materials to hand. It would have been a 'trade' that a man would be concentrating on just this particular form of fencing. He would devise his tools and methods to suit the material and form. He may well have chosen his wood felled it and prepared it or even grown it. The hurdle-maker in the past would adapt some of his wood for other tasks like pegs, spars, sticks, wattle, pea-sticks, brooms etc. He may have worked on his own or as one of a team.

Constructing a Hurdle
1.	Hazel is cut all the year round except mid-April to Mid-June - when the sap is rising. The cut hazel is then sorted and stacked for partial seasoning. When half dried the hurdle maker cuts, splits, and separates his stock - to form the poles, stakes, and rods. 2.	The hurdle maker would weave his hurdles on a sail which is nine 130cm (traditional hurdles were only 100cm high) uprights slotted into a curved line of holes (the first and last upright poles extend below the block by 30cm), 20cm apart, made in a heavy block of timber 240cm by 30 x 15 (hurdle block). The first and last uprights are stouter (15cm) brown poles to give strength whilst the other seven are split stakes. The slight curve in the set of holes, enable the hurdle - when drying out, to tighten up… This tightening up straightens the hurdle as it further seasons. The block and uprights are called the hurdle maker’s sail. 3.	He would first weave onto the sails a series of layers of slender brown rods (brown indicates that the bark is left on) bending and twisting to break some of the fibres, round the first and last pole (15cm thick) – to double back the weave to start the next layer. The first half dozen and last two layers are made of whole slender rods. The final two double twisted for extra strength. These control how ridged the structure will be, so it’s vital that they are tight and fast. The bending and twisting occurs for all courses in that construction of a hurdle. 4.	The previously made split rods are pushed or knocked down the sails, with the splits all facing the same way; down onto the first brown rods resting on the block, with a special knocking down tool. All layers are bent and twisted to 360 degrees round the first and last uprights – the white split face would all be facing the same way. 5.	Levering the made-up hurdle out of its block it is set aside to further season and tighten up. When setting up the hurdle the exposed 15cm of each upright stake is pushed or knocked into the ground to support the fence and the first and last stake secured to a post to make the fence permanent.

Suitability of a hurdle for the job
The size of the hurdle has been considered on how well the fence fits into the landscape. It maybe, to act as a screen, backdrop, or to act as a feature. You will have to consider the action the wind is going to have and the amount of maintenance you are prepared to make. It s not normal practice to use nails, wire, or to tether the structure. In times past hurdles were not considered permanent features but as transportable stock proof, windproof, pens which the shepherd could easily guard or sort the ewes and lambs.

The appearance should compliment the position you have chosen – to compliment your garden. The uniqueness of a hurdle is its rusticity and its natural finish. That did not come into the equation for past craftsmen because their work centred upon practicalities and cost rather than on aesthetics. If you are thinking long-term you may consider putting in factory prepared stakes, posts, or poles set at regular and standard intervals. This is essential in you have to inset a new fence at a later date. A factory fence post will be durable after preservation treatment by dipping. Setting the posts in by back-filling with hardcore will ensure a well drained post and ridged structure. Remember that hurdles have a front and a back. The front in this case, brown – with the bark still on. If the structure is to be a permanent one you may think about putting in stakes immediately into the ground and then interweaving the brown rods without twisting or bending. Building a shaped top weather rail and pole caps will improve the life of the work.

If you are not able to provide your own wood and you have to ‘buy in’, depending upon whether you wish to have a certain type of prepared rod, split or whole, your costs are going to be more than a conventional fence. What is written here is describing the way things were done in the past and as they had been evolved through the ages they represent the knowledge of experience. The object is to build something which is going to last and not blow down at the first puff of wind. If you use poor material or insert wood which is already rotten you will have to reintroduce a new piece at some later date and that usually occurs at some inconvenient moment. The fence needs to be substantial and tightly interwoven.

As indicated, hurdles were not considered permanent fixtures. Their construction was rough and ready able to stand upto throwing on the back of a cart or carried from one spot to another. The shepherd carted his hurdles which were thrown up, stacked, and roughly tied together - to form a circular pen. Any fence over 120cm will have to stand a considerable amount of wind force for it will act like a sail – put enormous pressure on the posts. It is obviously better to make the hurdles where they are going to be used.

The Structure of Timber
All plants are composed of cells of different shape (some conduct sap, others form bulk, the third stores food). This space maybe empty, contain liquid or be crystalline. The cells of wood are cemented together. It is the type and distribution of the cells, which define the quality, and behaviour of the particular species of timber. Timbers, which are ‘hard’, have small cell cavities with thick walls.

New tissues are formed by specialist cells dividing, into two halves, one half enlarging the other dividing. Food is obtained first from the roots – which takes in by absorption water and dissolved mineral salts. The minerals suspended in water are taken up the tree by perforated tube-shaped conduction cells called tracheae, or pores, to the leaves. The leaves take in carbon dioxide from the air which together with the dissolved salts suspended in water from the roots manufactures starch… The plant turns starch into sugar by the use of an enzyme, and sugar by light - acting on the chlorophyll, the green starch matter, by photosynthesis.

The food is transported in solution to all the growing tissues within the tree by pits in the cell walls. These radial rows of cells, called phloem or bast, lie immediately beneath the bark...  forming new cell walls parallel to the axis of the stem. Cells cut off furthest from the outside enlarge and thicken ultimately to form the wood. Growth rings occur at the end of each growing season – recognised by cell fibre and walls. Rays are parenchyma, food storage cells – cells that running across the grain.

When first formed the wood cells are thin-walled all similar in shape containing protoplasm. They quickly modify – the cell walls thicken and harden by depositing lignin. When this modification is complete the protoplasm dies.

When cutting the cleft in the wood - to bend over at right angles - to lay the hedge ,it is most important not to completely sever or destroy the phloem or cambium on the opposite side... which will still carry the food to the leaves.

Acknowledgements
Tudor House Construction, English country furniture and Field and Forest Crafts are so closely integrated that they both share related publications. Kept close to hand has been The Building Conservation Directory published by Cathedral Communications Limited. Individual specialist publications, from the Weald and Downland Museum and British Timbers by Boulton and Jay, published by Adam and Charles Black, 1946. The English Gardening School by Rosemary Alexander & Anthony du Gard Pasley, published by Michael Joseph Ltd., 1987. Tales of the Old Woodlanders by Valerie Porter, published by David & Charles, 1994.