Hedgerow

Hedgerow, closely planted line of woodland trees and shrubs originally used to mark boundaries, particularly those of farms and parishes in the British countryside. Hedgerows are found outside of the United Kingdom but not to any great extent. They are not natural features, as they were either planted, or left as a line of vegetation when surrounding woodland was cut down. Most of the British hedgerows were planted in the 18th and 19th centuries, when the farming landscape was divided into small fields, or “enclosures” (see Agricultural Revolution).

When most farms grew arable crops and also kept livestock, the farm hedgerows needed to be dense and thorny— to keep livestock separated from the crops. Hawthorn and other spiny shrubs were planted, but other species of trees and shrubs from the surrounding countryside were gradually able to establish new seedlings in the shelter of the hedges.

Hedgerows can be thought of as continuous ribbons of very narrow woodland habitat. Trees such as elm, ash, and oak cast shade, while native shrubs provide blossom, berries, protected nest sites, and shady shelter for ground-dwelling plants and animals. Generally, a new plant species establishes itself in a hedgerow every 30 years. By counting the number of different kinds of tree and shrub in a stretch of hedgerow it is possible to work out its age. For example, ten different species in 30 m (98 ft) of hedge suggests that the hedge is about 300 years old. Plant species commonly found, in addition to hawthorn, are field maple, wild rose, dogwood, ash, oak, elm, wild privet, holly, and crab apple. The oldest hedgerows were established when the surrounding countryside was still rich in woodland wildflowers, and as a result, woodland species such as foxgloves (see Digitalis), pink campions, bluebells, and even primroses, still grow wild in the hedgerow habitat.

The animal life of hedgerows is also a legacy from woodland. Badger sets often have their entrances in the hedge bank among the roots. Hedgehogs hunt along the field boundary and hibernate under the fallen leaves, while wood mice and bank voles provide food for stoats and weasels. Woodland butterflies are also found along hedgerows.

If a hedge is simply left to grow, it will quickly produce tall stems and leave gaps at ground level. For this reason, hedgerows have always needed careful management. For centuries, hedges were “laid” every few years. The stems were partly cut at ground level, and then pulled over by hand and woven together to form a dense living fence. Farm labourers carried out the work during the winter months when they did not have to cultivate the land and the animals were housed indoors. Today, most managed hedgerows are kept dense and bushy using machines. However, during the second half of the 20th century, many hedges were neglected because of the cost of maintenance, or removed to create larger fields. Farmers have also uprooted them because they limit the size of field machinery that they can use. It has been suggested that the shelter of hedgerows can help prevent soil erosion, but this theory is now being questioned, leaving the farming value of hedgerows in some doubt. The countryside of England and Wales once had 750,000 km (466,000 mi) of hedgerow. Since World War II this length has been halved. Over 12,800 km (7,954 mi) of hedgerow was lost between 1986, when the government first announced plans to conserve them, and 1997, when legislation to protect the remaining hedgerows was finally passed. Some new hedgerows are also being planted, although mostly for their landscape and conservation value rather than their fundamental use in farming.