In the Arboretum Today
By Alfredo Chiri

CHESTNUT - Castanea sativa - Fagaceae

Var. hybrid donated by: CRFG/Haluza and planted in 1981 (r.f.-09)

Var. Spanish donated by: CRFG/Haluza and planted in 1981 (r.f.-09)

Common names: Spanish Chestnut, Castaña Española, European chestnut

The European chestnut is probably a native of western Asia, from Iran to the Balkans, where it has been cultivated for more than 3000 years. The European chestnut is now called Spanish chestnut, as it has become naturalized throughout southern Europe from Spain to the Caucus.

The Spanish chestnut is a large tree that can reach a height of 100 feet, and in some old trees the trunk can have a diameter in excess of 10 feet. The leaves have coarse marginal teeth and prominent veins. The flowers are spike-like creamy catkins. The fruit is a prickly burr enclosing 1 to 5 nuts. There are many cultivars that yield a burr with a single large nut, called a marron in French.

Spanish chestnut, once established, is tolerant of drought. It does well in well-drained soils and tolerates acid soils. The tree prefers full sun. If the chestnut tree, while young, is kept in a dry environment, it may remain as a shrub and never grow to tree size.

Chestnuts are propagated generally by drafting onto seedlings. The seedlings are produced from sowing fresh seeds. Dried seeds may not germinate.

Spanish chestnut is susceptible to chestnut blight. The devastating fungus was introduced into the USA around 1900, and within 40 years it had killed every mature American chestnut (C. dentata) on the continent. The Spanish chestnut, for some reason, is more resistant to the chestnut blight than the American chestnut and grows easily in the western states.

The Spanish chestnut is a magnificent shade tree for parks, large estates, and boulevards. Blight-resistant varieties should be selected in cooler, wetter summer areas. If you want to grow chestnuts in California, the blight-resistant Japanese chestnut (C.crenata) and the Chinese chestnut (C. mollissima) would be a recommended choice.

The American chestnut (C. dentata) grows primarily in the eastern states but not in the prairie regions. The Indians of New England mixed chestnuts with pottage. Chestnuts now appear in season in all our markets and are sold roasted. The American variety bears smaller and sweeter nuts than the European.

The Portuguese chestnut (C. vesca) grows primarily in Brazil and prefers soils that are basic in nature and does not tolerate acidity. 

The nuts are rich in starch, oil, vitamin B1, B2 and C. Nuts can be roasted or boiled. Chestnuts are ground into flour to be used to thicken soups, stuffing, and stews. The leaves, twigs, bark, flowering catkins, and the spiny burr have been known to be used as astringents in healing wounds.