Hedges were invented to make natural boundaries to fields. Most hedges date from the time when land was changed from open fields to enclosed fields. This began in late medieval times, and continued through to Victorian times.
Some trees were allowed to grow to full height in the hedges because they were intended to be used for timber. Oaks are often dotted along old hedges.
Many hedges are dominated by a few types of tree. These are mainly naturally dense, and low growing trees that also have spines on their twigs. Hawthorn is a common one.
Hedges can also be made from trees that will regrow lots of shoots if cut down. Hazel and willow are like this. Hazel is a fast-growing tree. If it is cut down, it will produce many flexible saplings, and these can be bent or partly cut and intertwined to make a hedge that is more like a fence. Cutting down trees regularly is called coppicing. Hedges made using coppiced materials take a lot of work, and are not often used nowadays.
The most common hedge maintenance technique is with a tractor and a large hedge 'mower'. This rotating cylinder of blades can cope with quiet chunky wood, and is fast. The hedges that regrow quickly with many small twigs can be cut this way.
Hedges were meant as field boundaries, and so only needed to be narrow. But in the countryside, much of the natural forest has been lost, and the forests that remain are often isolated from one another. This means that wildlife does not have an easy way of getting about when looking for food. Animals like hedgehogs, and voles need shelter from birds if they are to survive.
In the 1960s and 70s, when big machines were developed to plough fields and harvest crops, many hedges were uprooted to make bigger fields for these big machines. This caused a lot of loss for wildlife, and most people now agree that it was a mistake. So there is some attempt to replant hedges.
As a result, hedges are now seen as wildlife corridors between forests, or even as just wildlife refuges where there are no forests. The hedges are also planted double thickness to provide more cover for animals, while the flowers that appear each year give food for insects.
Hedges are one of the easiest ways of bringing back some wildlife to the countryside, and even to towns and cities. They are best if they contain a range of species of plant, as that will provide food for a greater range of animals.
