Culture
Grow in moist, deep, well-drained loams in full sun. Tolerant of summer heat and humidity. Established trees do well in dry conditions. If growing this tree at least in part for its edible nuts, planting more than one tree facilitates cross-pollination (single trees are close to being self-sterile) and generally produces a much more abundant nut crop.
Noteworthy Characteristics
Native to Japan, Chinese chestnut is a small to medium sized, broad, low-branched, deciduous tree that typically grows 30-40' tall with an open rounded crown. It is primarily grown as an ornamental tree. Its nuts are large and edible, but with a bitter flavor (high tannin content), and are generally considered to be much inferior in flavor to other chestnuts in the genus. Japanese chestnut is noted for having resistance to chestnut blight which is the disease that has nearly wiped out the native American chestnut (see Castanea dentata). Oblong-lanceolate, toothed, dark green leaves (3-7” long) are pubescent beneath. Leaves turn varying shades of yellow and bronze in fall. Aromatic, monoecious, creamy yellowish-white flowers appear in catkins in late spring (May-June in St. Louis), the male flowers located at the top portion of the catkin and the female flowers located near the base. Flowers can be quite showy, albeit for a brief period. Flowers are followed by edible chestnuts which are encased in spiny dehiscent burs (2-3” diameter), usually 2-3 nuts per bur. Nut size is variable (from 2" diameter to much smaller). When the chestnuts are ripe, the burs turn yellow and split open. Although Japanese chestnuts are sometime sold in farmers’ markets, it is the Spanish chestnut, Castanea sativa, that produces the chestnuts most often sold commercially in the U.S.
Genus name comes from the Latin name for this tree which was derived from the town of Castania in Thessaly where the trees reportedly grew in abundance.
Specific epithet means with a rounded scalloped edge.
Problems
Japanese chestnut is resistant, but not immune, to chestnut blight (Endothia parasitica) which is a fatal fungal bark disease. Also susceptible to leaf spot, anthracnose and twig and stem cankers. Weevils can be a problem in some areas.
Uses
A beautiful specimen shade tree for lawns. Unfortunately, as is the case with the fruit of the sweet gum but perhaps more so, falling chestnuts can pose a significant litter problem, and often make walking barefoot in the lawn a real adventure. On the positive side, the chestnuts may be harvested for roasting on an open fire as it were.