Chestnuts are a large, quick growing forest tree. The Italian and Greek communities love them roasted, baked, boiled and in sweets. Rumours have mature trees dropping over a thousand dollars worth of nuts per year.
Most old chestnuts are seedlings of the Spanish chestnut (Castanea sativa). The Chinese chestnut (C. mollissima), the Japanese chestnut, (C. crenata) and the American, or Sweet chestnut (C. dentata) also produce edible nuts. The Horse chestnut is poisonous. In the United States, Chestnut Blight has all but wiped out the chestnut. Fortunately, Australia's strict quarantine laws have kept this disease at bay.
Chestnuts prefer moist growing conditions and shelter from hot, drying winds. Drainage must be good to avoid root rots, to which they are very susceptible.
Chestnuts used to be planted about 15-20 m apart, but now that selected varieties are becoming available, closer planting is becoming common. Planting distances of 5-10 m apart are being used to stimulate bearing earlier. The young tree is trained to a 1.5 m high trunk with three main leaders left to form an open crown. Further pruning is confined to removing competing shoots.
Pollination is problematic as there is no long-term experience as yet. The chestnut flowers are pollinated by the wind. Male and female flowers are separate. Some are poor pollen producers and so require a nearby variety that will overcome the shortfall.
Chestnuts fall from the tree after they mature. They are then gathered as soon as possible and the husks removed. As the husks are very spiky, gloves are a virtual necessity. Damp husks make removal considerably easier. Expect yields in the range of 100-150 kg per tree, though large old trees can yield twice these amounts.
Storage is generally in ventilated polythene bags. The nuts must not be allowed to dry out, or they will shrivel and become hard. Optimum storage temperature is in the range 3-5 degrees Celsius. Dry peat moss between the bags will absorb the moisture created by the nuts 'sweating'.
The major pests are parrots, possums and people. The latter are the most difficult to control. One nut grower acquaintance told me that upon accosting a family gathering some of his crop, one said, "Oh, we come here every year for chestnuts".