Belfast Botanic Gardens Tree Archive

Castania sativa
Sweet chestnut

Tag 244
54 deg 34.924N
5 deg 56.043W

The sweet chestnut, so called to distinguish it from the inedible horse chestnut (Aesculus hippocastanum) is a native of Southern Europe. Its fruit is enclosed in a spiny cupule and has a tough leathery outer shell. The nut is a valuable food source. As well as being roasted over coals on city streets throughout Europe in winter, it is the basis of marrons glace and can be ground to a flour. The timber is also very valuable. Large timbers, with a strength rivalling oak, are used in many historic buildings in France (both the wood and the tree are called Chataignier). Chestnut trees are also traditionally coppiced and allowed to grow to make poles of about 5cm diameter. These are used in hop farms, for charcoal production and split to make chestnut paling fencing. There used to be extensive coppiced chestnut woods in Kent to supply the hop farms there.

Sweet chestnut trees are easily distinguished in summer by the very long, toothed, leaves. In winter the furrowed bark which almost always spirals round the stem helps to distinguish them. In Northern Ireland the Castania will very seldom produce edible-sized nuts. The large nuts sold in shops are from varieties specially bred for nut production.