Bethlehem Wood:
The charcoal burner's encampment

On one side of Bethlehem Wood, there's a large rusty cylinder with a chimney and a woven hut. This is the Charcoal Burner's Encampment. The cylinder is the kiln and the woven structure is living quarters. All around there are sections of wood, ready for specialised burning.

Charcoal production is very much part of traditional woodland management, practised all over Wakehurst Place and especially in the Loder Valley Nature Reserve. The mainstay of traditional woodland management is coppicing.

With coppicing, a tree is cut to the ground for one use; then the shoots that spring from its trunk and roots are harvested for other uses. Pollarding is coppicing, but higher up the tree trunk, to prevent animals from grazing on the new growth.

With both methods, trees are cropped to meet particular needs, producing young willow withies for basket-making, older hazel poles for hurdles and hardwood logs for charcoal production. Importantly, it also benefits the woodland by letting light in to create the undergrowth which is an important wildlife habitat.

For charcoal production, hardwoods such as oak are coppiced on a 25-35 year cycle. Charcoal is made by heating wood without enough air to burn it completely into ash. Wakehurst's portable steel kiln is moved around from coppice to coppice and is filled with carefully-arranged logs. A little wood is burnt in the kiln to get it to working temperature and then, when the lid is put on and sealed, water boils out of the remaining wood, along with volatile tars and oils; leaving charcoal of up to 90% carbon. If air-dried wood is used, with a moisture content of less than 30%, then 4 tonnes of wood produces 1 tonne of excellent quality charcoal. Wakehurst produces and sells 3 tonnes of charcoal a year, the profits going back into conservation work.

Charcoal is used in Britain for domestic barbecues, in fireworks and in medicinal biscuits. Because of its ability to absorb gases and impurities, it is also used in chemical, water and vodka filters. Every year, some 60,000 tonnes of charcoal are sold in the UK, of which two-thirds are for barbecues. Only 3% (1,800 tonnes) is produced in Britain, yet there are huge supplies of low value wood available - an estimated 80,000 tonnes in south-east England alone.

Sadly, this means that much of what is sold is harvested unsustainably, so buying British hardwood charcoal, such as the Wakehurst-produced Bar-B-Kew brand, is the only way to be sure that imported wood from endangered tropical forests or mangrove swamps is not being used.

Continue the tour

Back up to: Woodland Zone

Carry on to: Rock Walk