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Climate and seasonal germination cycle

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. Chestnut is hardy to USDA zone 5, which is −29 °C (−20 °F) lower in average minimal temperature than London in zone 9. 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 750 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.