Chestnuts produce a better crop when subjected to chill temperatures during the dormant period. Frosts and snowfalls are beneficial rather than harmful to the trees. The dormant plant is very cold-hardy in Britain, to the Royal Horticultural Society's H6 hardiness rating, to -20 °C. and grows well throughout the country, north to northern Scotland. The young growth in spring, even on mature plants, however, is frost-tender; bud-burst is later than most other fruit trees, so late frosts can be damaging to young buds.
Trees can be found at altitudes between 200 and 1000 m above sea level; some mention between 300 and 759 m altitude, while the famous Hundred Horse Chestnut on Mount Etna stands at 1200 metres. They can tolerate maritime exposure, although growth is reduced.
Seeds germinate in late winter or early spring, but the life length is short. If kept moist, they can be stored in a cool place for a few months, but must be checked regularly for signs of germination. Low temperature prolongs dormancy. Sowing them as soon as ripe is better, either in cold frames or seedbeds outdoors, where they can be left in situ for one to two years before being planted in their permanent positions, or in pots, where the plants can be put out into their permanent positions in summer or autumn. They must be protected from the cold in their first winter, and also from mice and squirrels.
Chestnuts are considered self-sterile, so at least two trees are needed for pollination.
Soil requirements
Castanea grows best in a soil with good drainage and adequate moisture. The tree prefers sloping, deep soils; it does not like shallow or heavy soils with impermeable, clay subsoils. The Chinese chestnut prefers a fertile, well-drained soil, but it grows well in fairly dry, rocky, or poor soils.
Although Castanea can grow in very acidic soil, and while these soils are reasonably well tolerated, the preferred range is from pH 5.5-6.0. It does not grow well on alkaline...
