Common Name: Sweet Chetsnut

General Information

Castanea sativa is a deciduous tree usually growing up to 30 metres tall, occasionally reaching 40 metres[].
The sweet chestnut has a long history of cultivation, with evidence to show that it was being grown in Italy around 4,000 BCE. It is frequently cultivated as a nut tree, especially in Mediterranean countries, though it is also frequently planted in the southern states of the USA and in the Crimea, the Caucasus and Turkey. The tree is also managed as a coppice in order to provide wood for fuel, fencing and various other purposes.

Known Hazards

None known

Botanical References

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Range

Southeastern Europe to western Asia - the Balkans, through Greece to Turkey, Lebanon, Syria, the Caucasus and northern Iran

Habitat

Woods in mountains[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Growth Rate	Medium
Pollinators	Wind, Bees, Insects
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Castanea sativa is a very cold-hardy tree, tolerating temperatures down to around -25°c when dormant. It grows best in areas with hot summers - in cooler areas, such as the maritime regions of the temperate zone, it usually grows well but often fails to produce large, good quality fruit[, ]. Requires a minimun annual precipitation of 600 - 800mm[]. Young growth in spring can be damaged by late frosts[].
Prefers a good well-drained slightly acid loam in a sunny position but it also succeeds in dry soils[, , , ]. Once established, it is very drought tolerant[, , , ]. Plants are very tolerant of highly acid, infertile dry sands[]. Averse to calcareous soils but succeeds on harder limestones[, ]. Tolerates maritime exposure though it is slower growing in such a position[].
The sweet chestnut is often cultivated for its edible seed in warm temperate zones, there are several named varieties[, ]. Both 'Marron de Lyon' and 'Paragon' produce fruits with a single large kernel (rather than 2 - 4 smaller kernels) and so are preferred for commercial production[].
At one time this tree was widely grown for its wood in coppiced woodlands in Europe. This was used to make small items, especially fence posts, and also to provide wood for fuel. Howeve, trhe practise of coppicing has fallen into virtual disuse[].
Trees regrow very quickly after being cut down, and are able to produce utilizable timber every 10 years.
Flowers are produced in summer on wood of the current year's growth[]. They may be pollinated by the wind (which is the more usual method if the weather is dry during flowering) or by insects (which is more common in wet weather conditions)[]. The flowers are rich in pollen and nectar, and are very attractive to bees[].
Plants are fairly self-sterile[].
All the different Castanea species are interfertile and will hybridize freely with other members of this genus[].
This species is not often seen in Cornwall though it grows very well there[].
A very long-lived tree, with specimens known to be more than 1,000 years old. Such old specimens can have huge boles 4 metres or more in diameter[].
Trees take 30 years from seed to come into bearing[].
Plants in this genus are notably resistant to honey fungus[].

They are eaten roasted, dried or candied (marrons glacés), the flour is used in cooking, especially in Italy. Bark extracts are used in tanning. Sometimes planted for erosion control in Mediterranean countries and as bee fodder plant, as park tree in many further countries. Chestnuts are frequently attacked or destroyed by chestnut blight. Interspecific hybrids (C. Sativa × C. Crenata, and C. Sativa × C. Mollissima) have been planted in France, that may have improved resistance to chestnut blight (Cryphonectria parasitica) and ink disease (Phytophthora spp.)[].

Edible Uses

Seed - raw or cooked[, , , , , ]. A somewhat astringent taste raw, it improves considerably when cooked and is delicious baked, with a floury texture and a flavour rather like sweet potatoes[]. The seed is rich in carbohydrates, it can be dried, then ground and used as a flour in breads, puddings, as a thickener in soups etc[, , , ].

The roasted seed can be used as a coffee substitute[].

A sugar can be extracted from the seed[].

Medicinal

Although more commonly thought of as a food crop, sweet chestnut leaves and bark are a good source of tannins and these have an astringent action useful in the treatment of bleeding, diarrhoea etc.
The leaves and bark are anti-inflammatory, astringent, expectorant and tonic[, , ]. They are mainly employed for their efficacy in treating convulsive coughs such as whooping cough, and in other irritable conditions of the respiratory system[, ]. An infusion has also been used in the treatment of fevers and ague[, ].
The leaves can also be used externally in the treatment of rheumatism, to ease lower back pains and to relieve stiff muscles and joints[]. A decoction of the leaves is a useful gargle for treating sore throats[].
The leaves are harvested in early summer and can be used fresh or dried[]. The bark is usually harvested when the tree is dormant, but can be taken at any time.

The leaves are used in homeopathy and are considered to be a useful remedy in the treatment of whooping-cough[].

The plant is used in Bach flower remedies - the keywords for prescribing it are 'Extreme mental anguish', 'Hopelessness' and 'Despair'[].

Agroforestry Uses:

Castanea sativa is an excellent soil-enriching understorey plant to grow in open pine forests[].

Other Uses

Tannin is obtained from the bark[, ]. The wood, leaves and seed husks also contain tannin[]. The husks contain 10 - 13% tannin[]. On a 10% moisture basis, the bark contains 6.8% tannin and the wood 13.4%[].

The meal of the seed has been used as a source of starch and also for whitening linen cloth[].

A hair shampoo is made from the leaves and the skins of the fruits[]. It imparts a golden gleam to the hair[].

The wood is light in weight, hard, strong and very durable. Older wood can become brittle and liable to crack[]. An excellent wood, it is used for carpentry, furniture making, turnery, mine props, cooperage, shingles, basketry, fence posts etc[, , , , , , ].
The wood is a very good fuel, burning well and giving off a lot of heat[].

Propagation

Seed - where possible sow the seed as soon as it is ripe in a cold frame or in a seed bed outdoors[]. The seed must be protected from mice and squirrels. The seed has a short viability and must not be allowed to become dry. It can be stored in a cool place, such as the salad compartment of a fridge, for a few months if it is kept moist, but check regularly for signs of germination. The seed should germinate in late winter or early spring. If sown in an outdoor seedbed, the plants can be left in situ for 1 - 2 years before planting them out in their permanent positions. If grown in pots, the plants can be put out into their permanent positions in the summer or autumn, making sure to give them some protection from the cold in their first winter[].