This handsome Spanish chestnut stands guard at the Atlanta Botanical Garden in Atlanta, Georgia.
Spanish chestnut is a large and handsome tree that can get 100 ft (30.5 m) tall with a crown spread about half its height. Really old trees may have a trunk diameter in excess of 10 ft (3.1 m). The oblong-elliptic leaves grow to 8 in (20.3 cm) long and have coarse marginal teeth and prominent veins. The flowers are in showy spikelike creamy yellow catkins. The fruit is a prickly burr enclosing 1-5 nuts each 0.5-1 in (1.3-2.5 cm) in diameter. There are numerous cultivars selected for nut quality and adaptation to different regions and growing conditions. The finest cultivars yield a burr with a single large, sweet nut, called a marron in French. Cultivars selected for ornamental use include 'Albomarginata' with white-margined leaves, and 'Aspleniifolia' with deeply dissected, featherlike leaves.
The chestnuts are found inside these burrs.
Spanish chestnut was probably originally native to western Asia, from Iran to the Balkans. It has been cultivated for more than 3000 years, and today it occurs in wild or naturalized populations throughout S Europe, N Africa and SW Asia. The common name probably derives from the fact that the some of the best chestnuts imported into England were grown in Spain.
Spanish chestnut is susceptible to chestnut blight, the devastating fungus disease that was introduced into North America from Asia around 1900 and within 40 years had killed every mature American chestnut (C. dentata) on the continent. Spanish chestnut is not quite as susceptible to chestnut blight as is American chestnut, and apparently the disease cannot tolerate the cooler, wetter summers of northern Europe, England and the American Pacific Northwest. For some reason, chestnut blight kills Spanish chestnuts almost everywhere in North America but hardly at all in Europe. If you want to grow chestnuts in North America you are limited to blight resistant Japanese chestnut (C. crenata), Chinese chestnut (C. mollissima) and hybrids that are resistant to chestnut blight. Light: Full sun. Moisture: Spanish chestnut, once established, is tolerant of drought. It does best in sandy, well drained soils and is highly tolerant of acidic soils. If kept too dry when young, Spanish chestnut may remain as a shrub and never grow to tree size. Hardiness: USDA Zones 5 - 7. Propagation: Chestnuts are generally propagated by budding or grafting on seedling stock. The seedlings are produced by sowing fresh seeds. Dried seeds may not germinate.
Detail of Spanish chestnut bark.
The Spanish chestnut is a magnificent huge shade tree for parks, estates and avenues. It is quite showy in bloom. They are common in England and most of the Continent. Chestnuts have both male and female flowers on the same tree but they are largely self-incompatible so you need at least two trees to get nuts.
Chestnuts have less oil and more starch than most nuts and so are used differently in cooking. Roasted chestnuts are a wintertime favorite on both sides of the Atlantic.
Spanish chestnut is the source of most of the edible chestnuts marketed in the U.S. Throughout most of Europe cultivated chestnuts (marrons) are an expensive gourmet food. In contrast, wild (or feral) chestnuts are widely enjoyed. In southern Europe, they make a flour from chestnuts that is similar to wheat flour in protein, starch and fat but lacks the gluten; breads and cakes made with chestnut flour tend to fall apart unless some wheat flour is added. The Italians made polenta from chestnut flour before the introduction of corn from the New World, and before potatoes were introduced, chestnuts were the basic food of the poor in much of southern Europe.