Chestnut

Chestnut
Sweet Chestnut Castanea sativa
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Fagales Family: Fagaceae Genus: Castanea
Species
Castanea alnifolia - Bush Chinkapin* Castanea crenata - Japanese Chestnut Castanea dentata - American Chestnut Castanea henryi - Henry's Chestnut Castanea mollissima - Chinese Chestnut Castanea ozarkensis - Ozark Chinkapin Castanea pumila - Allegheny Chinkapin Castanea sativa - Sweet Chestnut Castanea seguinii - Seguin's Chestnut * treated as a synonym of Castanea pumila by many authors

Chestnut (Castanea),^[1] (including some chinkapin or chinquapin) is a genus of eight or nine species of deciduous trees and shrubs in the Beech family Fagaceae, native to temperate regions of the Northern Hemisphere. The name also refers to the edible nuts they produce.^[2][3][4]

Contents 1 Species 2 Etymology 3 Description 4 History 4.1 Europe 4.2 North America 4.3 Australia, New Zealand 4.4 Asia 5 Nutrition 6 Cultivation, pests and diseases 6.1 Climate, seasonal germination cycle 6.2 Soil requirements 6.3 Sun exposure 6.4 Watering 6.5 Preservation 6.6 Pests 6.7 Diseases 7 Uses 7.1 Culinary 7.2 Animal fodder and litter 7.3 Medicinal properties 7.4 Timber 7.5 Coppicing 7.6 Fuel 7.7 Sustainable forest management|Forestry]] 7.8 Wildlife 7.9 Other uses 8 Artistic references 9 Famous Chestnut trees 10 References 11 External links

Species

The Chestnut tree (Castanea) belongs to the same Fagaceae family as the Oak and Beech trees. There are four main species, commonly known as European, Chinese, Japanese and American Chestnuts^[5]:

• Sweet Chestnut (Castanea sativa) (called "Spanish Chestnut" in U.S.A.) is the only species of European Chestnut.
• Asiatic Chestnut species comprise Castanea crenata (Japanese Chestnut), Castanea mollissima (Chinese Chestnut), Castanea davidii (China), Castanea henryl (Chinese chinkapin, also called Henry's Chestnut – China) and Castanea seguinii (also called Seguin's Chestnut - China).
• American species include Castanea dentata (American Chestnut - Eastern states), Castanea pumila (American- or Allegheny Chinkapin, also known as "Dwarf Chestnut" - Eastern states), Castanea alnifolia (Southern states), Castanea ashei (Southern states), Castanea floridana (Southern states) and Castanea paupispina (Southern states).^[6][7]

Chestnuts should not be confused with either Horse Chestnuts (genus Aesculus), or Water Chestnut (family Cyperaceae); these are unrelated to Castanea and are named for producing nuts of similar appearance but of no notable edibility in the case of the former, and tubers of similar taste from an aquatic herbaceous plant in the case of the latter.^[8][9] Other trees commonly mistaken for the Chestnut tree are the Chestnut Oak (Fagaceae Quercus prinus) and the American Beech (Fagus grandifolia).^[10][11]

Etymology

For some, the name Castanea is derived from the old name for the Sweet Chestnut, either in Latin^[12] or in Greek. For others the name comes from that of the town of Kastania in Thessaly, Greece;^[6] but it is more probable that on the contrary the town took its name from the most common tree growing around it.^[13] Among the Mediterranean climate zone, chestnut trees are rarer in Greece because they dislike chalky soils. Kastania is located on one of the relatively few sedimentary or siliceous outcrops. They grow so abundantly there, that the strangeness of the fact would have determined the place's name. ^[14] Still others take the name as coming from the Greek name of Sardis glans (Sardis acorn) – Sardis being the capital of Lydia, Asia Minor, wherefrom the fruit had spread.^[15]
The tree's names are virtually identical in all the most ancient languages of Central Europe: in Breton "Kistinen" for the tree, and "Kistin" for its fruit, in Welsh "Castan-wydden" and "Sataen", and many others close to the French "châtaigne" and to the Latin name chosen for the genus.^[13]
The name is cited twice in the authorized version of the Bible. In one instance, Jacob puts peeled twigs in the water troughs to promote healthy offspring of his livestock.^[16] Although it may indicate another tree, all indicates that that fruit was a local staple food at that time.^[13]

The following synonyms are or have been in use: Fagus castanea (used by Linnaeus in first edition of Species Plantarum, 1753).^[17] Sardian nut. Jupiter's nut. Husked nut. Spanish Chestnut (U.S.).^[18]

Description

Chestnut trees are of moderate growth rate (for the Chinese Chestnut tree) to fast-growing for American and European species.^[18] Their mature heights vary from the smallest species of chinkapins, often shrubby,^[19] to the giant of past American forests, Castanea dentata that could reach 60m. In between these extremes are found the Japanese Chestnut (Castanea crenata) at 10m average (although this specimen shows that they can reach greater bulks); followed by the Chinese Chestnut (Castanea mollissima) at about 15 m, then the European Chestnut (Castanea sativa) around 30 m.^[11]

The Chinese and more so the Japanese Chestnuts are both often multi-leadered and wide-spreading,^[11] whereas European and especially American species tend to grow very erect when planted among others, with little tapering of their columnar trunk which is firmly set and massive. When standing on their own they spread on the sides and develop broad, rounded, dense crowns at maturity.^[18] The two latter's foliage has striking yellow Autumn colouring.^[20]

Its bark is smooth when young,^[21] of a vinous maroon or red-brown colour for the American Chestnut,^[13], grey for the European Chestnut. With age American species' becomes grey and darker, thick and deeply furrowed; the furrows run longitudinally, and tend to twist around the trunk as the tree ages – it sometimes reminds of a large cable with twisted strands.^[18]

The leaves are simple, ovate or lanceolate, 10-30 cm long and 4-10 cm broad, with sharply pointed, widely-spaced teeth, with shallow rounded sinuates between.^[8]

The flowers follow the leaves, appearing in late Spring or early Summer^[18] or onto July.^[19] They are arranged in long catkins of two kinds,^[19] with both kinds being borne on every tree.^[13] Some catkins are made of only male flowers, which mature first. Each flower has eight stamens, or 10 to 12 for Castanea mollissima.^[22] The ripe pollen carries a heavy sweet odour^[19] that some people find too sweet or unpleasant. Other catkins have these pollen-bearing flowers but also carry near the twig from which these spring, small clusters of female or fruit-producing flowers. Two or three flowers together form a four-lobed prickly calybium which ultimately grows completely together to make the brown hull, or husk, covering the fruits.^[18]

The fruit is contained in a spiny (very sharp) cupule 2 to 3 inches or 5 to 11 centimetres diameter, also called "bur" or "burr".^[23] The burrs are often paired or clustered on the branch^[19] and contain one to seven nuts according to the different species, varieties and cultivars.^{[2][3][24][25]} At around the time when the fruits reach maturity, the burrs turn yellow-brown and split open in 2 or 4 sections. They can remain on the tree longer than they hold the fruit, but more often achieve complete opening and release the fruits only after having fallen on the ground and partly due to soil humidity.^[7]

The chestnut fruit has a pointy end with at the tip a small tuft called 'flame' in Italian^[7], and a hilum – an oblong spot at the other end of the fruit. In many varieties the fruit is flattened on one or two sides. It has two skins. The first one, is a hard outer shiny brown hull or husk, called the pericarpus;^[26] the industry calls it 'the peel'.^[7] Underneath the pericarpus is another thinner skin, also called "pellicle" or "episperm".^[26] The pellicle closely adheres to the seed itself, following the grooves usually present at the surface of the fruit. These grooves are of variable sizes and depth according to the species and varieties. They make the peeling in most cases difficult without the appropriate technique – (external link).^[27]
The fruit inside these shows two cotyledons with a creamy-white flesh throughout,^[9] except in some varieties which show only one cotyledons, and whose episperm is only slightly if not intruded at all. Usually these varieties have only one large fruit per burr, well rounded (no flat face) and which is called "marron"^[7] ("Marron de Lyon" in France, "Marron di Mugello" in Italy, "Paragon", ...).

The superior fruiting varieties among European Chestnuts have good size, sweet taste and easy-to-remove inner skins. American Chestnuts are usually very small (around 5 g), but sweet tasting with easy-to-remove pellicles. Some Japanese varieties have huge nuts (around 40 g), with typically difficult to remove pellicles. Chinese Chestnuts' pellicle is usually easy to remove and their sizes vary greatly according to the varieties, although usually smaller than the Japanese Chestnut.^[11]

History

Europe

The sweet chestnut was introduced into Europe from Sardis, in Asia Minor; the fruit was then called the 'Sardian Nut'.^[18] It has been a staple food in Southern Europe, Turkey and southwestern and eastern Asia^{[9] [28]} for millennia, largely replacing cereals where these would not grow well, if at all, in mountainous Mediterranean areas.^[29] Alexander the Great and the Romans planted Chestnut trees across Europe while on their various campaigns. The Greek army is said to have survived their retreat from Asia Minor in 401-399 B.C. thanks to their stores of chestnuts.^[30] Ancient Greeks like Dioscorides and Romans such as Galen, wrote of chestnuts to comment on their medicinal properties – and of the flatulence induced by eating too much of it.^[31] To the early Christians chestnuts symbolized chastity.^[16] Until the introduction of the potato, whole forest-dwelling communities which had scarce access to wheat flour relied on chestnuts as their main source of carbohydrates.^[9] In some parts of Italy a cake made of chestnuts is used as a substitute for potatoes.^[6]
In 1583, Charles Estienne and Jean Liébault wrote that "an infinity of people live on nothing else but (the chestnut)".^[32] In 1802, an Italian agronomist said of Tuscany that "the fruit of the chestnut tree is practically the sole subsistence of our highlanders",^[33] while in 1879 it was said that it almost exclusively fed whole populations for half the year, as "a temporary but complete substitution for cereals".^[34]

Boundary records compiled in the reign of John already showed the famous Tortworth Chestnut in South Gloucestershire, as a landmark; and it was also known by the same name of “Great Chestnut of Tortworth” in the days of Stephen. This tree measured over 50 feet in circumference at 5 feet from the ground in 1720. The Chestnut forests on Mount Etna contain many trees that are said to be even larger. Chestnut trees particularly flourish in the Mediterranean basin.^[18] In 1584 the Governor of Genua, who dominated Corsica, ordered to all farmers and landowners to plant four trees yearly, among which a Chestnut tree – plus Olive-, Fig- and Mulberry-trees (this assumedly lasted until the end of Genoese rule over Corsica in 1729). Many communities owe their origin and former richness to the ensuing Chestnut woods.^[35] In France the marron glacé, a candied chestnut involving 16 different processes in a typically French cooking style, is always served at Christmas and New Year's time.^[16] In Italy they are still given to the poor as a symbol of sustenance on St. Martin's Day, November 11^[30] (in Modena soaked in wine before roasting and serving^[16]) and are also traditionally eaten on Saint Simon's Day in Tuscany.^[30]

Their popularity has declined during the last few centuries, partly due to their reputation of "food for poor people".^[36] Many people did not want to take chestnut bread as "bread" because chestnut flour does not rise. Some slandered chestnut products in such words as the bread which "gives a sallow complexion" written in 1770,^[37] or in 1841 "this kind of mortar which is called a soup"^[38] The last decades' worldwide renewal may have profited from the huge reforestation efforts started in the 30s in the United States, to establish a variety / varieties of Castanea sativa which may be resistant to chestnut-blight, as well as the strain on cereal supplies.

The main region in Italy for chestnut production is the Mugello region; in 1996 the European Community granted the IGP (Protected Geographic Indication; equivalent to the French Appellation d'Origine Contrôlée) status to the Mugello Sweet Chestnut. It is markedly sweet, peels easily, is not excessively floury or astringent, and has notes of vanilla, hazelnut and more subtly of fresh bread. There is no "unpleasant" aroma such as yeast, fungus, mold or paper, which sometimes occur with other chestnuts.^[39] The main regions in France for chestnut production are the départements of Ardèche with the famous “Châtaigne d’Ardèche” (A.O.C), of the Var, and of the Lyon region. France annually produces over 1,000 tonnes but still imports about 8,000 tonnes, mainly from Italy.^[40]

In Portugal's archipelago of Madeira, Chestnut liquor is a traditional beverage, and it's gaining popularity with the tourists and in continental Portugal.

North America

Native Americans were eating the American Chestnut species, mainly Castanea dentata and some others, long before European immigrants introduced their stock to America and before the arrival of Chestnut blight.^[30] In some places such as the Appalachian Mountains and others, one in every four hardwoods was an American Chestnut. Mature trees often grew straight and branch-free for 50 feet, up to one hundred feet, averaging up to five feet in diameter. For three centuries most barns and homes east of the Mississippi were made from American Chestnut.^[41] In 1911 the famous food book The Grocer's Encyclopedia noted that a cannery in Holland included in its "vegetables-and-meat" ready-cooked combinations, a "chestnuts and sausages" casserole besides the more classic "beef and onions" and "green peas and veal" - this to celebrate the chestnut culture that would bring whole villages out in the woods for three weeks each autumn (and keep them busy all winter), and to deplore the lack of food diversity in the United States's shop shelves.^[6]

This was not long before America would measure the extent of the impending catastrophe. The discovery of the Chestnut blight fungus on some Asian Chestnut trees planted on Long Island, New York was made public in 1904. Within 40 years the near-4 billion-strong American Chestnut population in Northern America was devastated^[42] – only a few clumps of trees remained in California and the Pacific northwest.^[30] Due to disease, American Chestnut wood almost disappeared from the market for decades, although quantities of Chestnut wood can still be obtained as reclaimed lumber.^[43] Today they only survive as living stumps, or "stools", with only a few growing enough shoots to produce seeds shortly before dying. This is just enough to preserve the genetic material used to engineer an American Chestnut tree with the minimal necessary genetic input from any of the disease-immune Asiatic species. Efforts started in the 1930s are still ongoing to repopulate the country with these trees, in Massachusetts^[44] and many places elsewhere in the United States.^[42]

Today, the fruit's demand outstrips supply. The United States imported 4,056 metric tons of European in-shell chestnuts worth $10 million in 2007.^[45] But the U.S. chestnut industry is as yet in its infancy, producing less than 1 percent of total world production. Since the mid-twentieth century, most of the United States's imports are from Southern Italy with the large, meaty, and richly flavored Sicilian chestnut being considered among the best qualities for bulk sale and supermarket retail. But some imports come from Portugal and France. The next two largest sources of imports to the United States are China and South Korea. ^[45] The French varieties of marrons are highly favoured and sold at high prices in gourmet shops.^[16]

Meanwhile, a 2005 study of the sector found that U.S.A. producers are mainly part-timers diversifying an existing agricultural business, or hobbyists.^[46] Another recent study indicates that investment in a new plantation takes 13 years to break even, at least within the current Australian market.^[47] But starting a small-scale operation demands only a relatively low initial investment, This is a factor in the small size of the present production operations, with half of them being within 3 to 10 acres. Another pre-determining factor in the small productivity of the sector, is that most orchards have been created less than 10 years ago so have young trees which are as now barely entering commercial production.^[46] Assuming a 10 kgs yield for a 10 year-old tree is a reliable conservative estimate, even though some exceptional specimens of that age have yielded 100kgs.^[47] So most producers earn less than $5,000 per year, with a third of the total not having sold anything so far.^[46]

Moreover, the plantings have so far been mostly of Chinese species, but the products are not readily available.^[46] The American Chestnut Foundation recommends holding on a little while more before large-scale planting. This is because it and its associates (the American Chestnut Cooperators' Foundation and many others from education, research and industry sectors contributing to the program) are at the last stages of developing a variety that is as close as possible to the lost American chestnut, while having incorporated the blight-resistant gene of the Asiatic species. Considering the added-value bonus that Chestnut trees can be easily grown organically^[46], and assuming the development of brands in the market, there is little doubt that everything else being equal, home-grown products would reach higher prices than imports – the high volume of which indicates a market with expanding prospects.^[46] As of 2008, the price for chestnuts sold fresh in the shell ranges from $1.50 per pound wholesale to about $5 per pound retail, depending mainly on the size.^[45][46]

Australia, New Zealand

The Australian gold rush of the 1850s and 1860s saw the first recorded plantings of European Chestnut trees, brought in from Europe by the first settlers.^[11] Along the years, most but not all Chestnut tree plantations were Castanea sativa stock, which is still the dominant species. Some of these are still standing today. Some trees in northern Victoria are around 120 years old and up to 60 meters tall.
Chestnuts grow well in the South-West of Western Australia, which has cold winters and warm to hot summers.^[9] As of 2008 the country has just under 350 Chestnut growers, annually producing around 1,200 tonnes of chestnuts of which 80% comes from North-East Victoria. The produce is mostly sold to the domestic fresh fruit market. Chestnuts are now slowly gaining popularity in Australia. A considerable increase in production is expected in the next 10 years, due to the increase in commercial plantation during the last fifteen years^[5] to twenty-five years.^[9] By far the most common species in Australia is the European Chestnut, but there are small numbers of the other species, as well as some hybrids.^[5]
The Japanese Chestnut (Castanea crenata) does well in wet and humid weather and in hot summers (~30oC); and has been introduced in New Zealand in the early 1900s, more so in the upper North Island region^[11]

Asia

Always served as part of the New Year menu in Japan, chestnuts represent both success and hard times – mastery and strength.^[16] The Japanese Chestnut (called Kuri) has been cultivated before rice-growing^[48], and the Chinese Chestnut (Castanea mollissima) possibly for 2-6,000 years.^[11] China has about 300 Chestnut cultivars, commonly divided into 5 populations: Northern, Yangtze River Valley, Sichuan and Guizhou, Southern and Southwestern. Moreover, the Dandong chestnut (belonging to the Japanese Chestnut – Castanea crenata) is a major cultivar in Liaoning Province.^[49]

Nutrition

Fresh chestnut fruits have about 180 Kcalories^[39] to 200 Kcal^[36] per 100 gr. of product; it is nevertheless much lower than that of walnuts, almonds, other nuts and dried fruit (about 600 Kcal per 100 gr).^[39] As any plant product, chestnuts contain no cholesterol^[50] It contains very little fat, mostly unsaturated. They contain no gluten.^[11]

Their carbohydrate content compares with that of wheat^[36] and rice; it has twice as much starch as that of the potato.^[30] In some areas Sweet Chestnut trees are called "the bread tree".^[39][51] When chestnuts are just starting to ripen, the fruit is mostly starch and is very firm under finger pressure from the high water content. As the chestnuts ripen, the starch is slowly converted into sugars; and moisture content also starts decreasing. Upon pressing the chestnut a slight 'give' can be felt: the hull is not so tense, there is space between it and the flesh of the fruit.^[52] The water is being replaced by sugars, which means better conservation.^[40]

They are the only "nuts" that carry vitamin C. One ounce of boiled or steamed chestnuts has 7 mg of vitamin C; dried chestnuts have more than double that amount with 16.6 mg. for one ounce,^[16] as much as the lemon.^[36] Fresh chestnuts have a very high water content: superior to 52%^[36], and a high transpiration rate similar to that of potatoes and onions. They can lose even 1% of weight in one day at 20°C and 70% relative humidity.^[7]

Tannin is contained in the bark^[53][54] as well as in the wood, leaves and seed husks. The husks contain 10 - 13% tannin.^[54]

The fruit also contains many other micro-nutrients:

Main known constituents – Chestnut fruit

Constituent	Quantities	Comparison with apple
Proteins	about 3 g/100g[51] to 4 g/100g.[36]	0.2 g/100g.[50]
Lipids	from less than 2 g/100g[51] to 2.6 g/100g.[36] No cholesterol[50]	0.1 g/100g.[50]
Glucids – starch	28 g/100g[40] to 44 g/100g.[7][51] They contain twice as much starch as the potato.[30]	xx
Glucids – soluble sugars	8.1 g/100g in soluble sugars, monosaccharides and disaccharides, mainly sucrose, glucose, fructose, and, in less amount, stachyose, and raffinose.[7] 3.3 g/100g.[50]	1.0 g/100g.[50]
Total carbohydrates	32.1 g/100g.[50]	14.0 g/100g.[50]
Ashes	1 g/100g.[36]	xx
Fibers	20 g/100g[51] ou 14.9 g/100g.[50]	0.1 g/100g.[50]
Water	High water content: superior to 52%.[36]	84.8%.[50]
Iron	1mg/100g [36] to 1.2mg/100g.[7] 0.7 mg/100g.[50]	0.3 mg/100g.[50]
Zinc	[36] 0.4 mg/100g.[50]	88 mg/100g.[50]
Copper	mentioned.[36]	xx
Manganese	mentioned.[36]	xx
Phosphorus	85mg/100g[36] to 89mg/100g.[7]	xx
Potassium	500 mg/100g.[7] 468 mg/100g.[50]	110 mg/100g.[50]
Magnesium	mentioned.[36]	xx
Sulfur	mentioned.[36]	xx
Sodium	mentioned.[36] 1.1mg/100g.[7] 0.8mg/100g.[50]	1.0 mg/100g.[50]
Calcium	38mg/100g[7] to 40mg/100g.[36] 17.6 mg/100g.[50]	7.0 mg/100g.[50]
Vitamin B1	mentioned.[36] (anti-beriberic, or aneurin, or thiamine) 0.22mg/100g.	xx
Vitamin B2	mentioned.[36] (riboflavin) 0.35 mg/100g.[7]	xx
Vitamin B3	(nicotinic acid, niacin or orniacin) 1.4mg/100g.[7]	xx
Vitamin C	50mg/100g, as much as in the lemon.[36]	xx

Cultivation, pests and diseases

Climate, seasonal germination cycle

Chestnut gives a better crop when subjected to chill temperatures during the dormant period. Frosts and snowfalls are beneficial rather than harmful to Chestnut trees.^[9][47] The dormant plant is very cold-hardy in Britain.^[55] Chestnut is hardy to zone 5, which is 22 degrees Celsius lower in average minimal temperature than London in zone 9.^[56] But the young growth in spring, even on mature plants, is frost-tender<;ref name= KenFern/>^[56]: bud-burst is later than most other fruit trees, so late frosts can be damaging to young buds.^[47]

It can be found at altitudes between 200 and 1000 metres above sea level^[47]; some mention between 300 and 750m altitude^[57], while the famous Chestnut Tree of One Hundred Horses on Mount Etna stands at 4000 feet altitude.^[58]). It can tolerate maritime exposure although its growth is reduced.^[56]

When grown from seed, the trees do not begin to yield fruit until they are thirty^[56] to forty years-old.^[30] Grafted trees can start bearing in their fifth year.
The seed germinates in late winter or early spring.^[55][56] The seed's life length is short. If kept moist, it can be stored in a cool place for a few months, but must be checked regularly for signs of germination.^[56] Low temperature prolongs dormancy.^[7] It is better sown as soon as it is ripe: either in a cold frame or seed bed outdoors,^[59] where it can be left in situ for 1 to 2 years before being planted in their permanent positions;^[56] 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^[55], and also from mice and squirrels.^[56]

Chestnuts are considered self-sterile^[56][60], so at least two trees are needed for pollination.^[52]

Soil requirements

Castanea likes a soil with good drainage and adequate moisture.^[52][47] The Chestnut tree prefers sloping, deep soils; it does not like shallow or heavy soils with impermeable, clay subsoils.^[47] The Chinese Chestnut prefers a fertile, well-drained soil, but it grows well in fairly dry, rocky, poor soils.^[61]
Although Castanea can grow in very acid soil^[56], and while these soils are reasonably well tolerated, the preferred range is from pH 5.5-6.0.^[47] It does not grow well on alkaline soils such as chalk^[12][56], but thrives on soils such as soils derived from granite, sandstone, or schist.^[12] On alkaline soils, Chestnut trees can be grown by grafting them onto oak rootstocks.^[43]
Recently cleared land is best avoided to help resist the root rot, Armillaria mellia.^[47]

Sun exposure

Castanea likes a full sun position.^[52] An experiment with Castanea dentata seedlings in Ohio confirmed the need for sun for optimal growth.^[62] The butt of the tree is sometimes painted with white paint to protect the tree from sunburn until it has developed enough canopy.^[47]
Wide spacing between the trees encourages low, broad crowns with maximum exposure to sunshine to increase fruit production. Where Chestnut trees touch there is virtually no fruit production. Current industrial plantings can range from 7m x 7m to 20m x 20m. The closer plantings, more popular, mean quicker increase in short-term production but "heavy pruning" or even "tree removal" later.^[47]

Watering

The optimum rainfall for Chestnut trees is 800mm+ per annum, ideally in even distribution throughout the year. Mulching during summer is recommended. Rainfall below 700mm per annum needs be complemented, for example with a drip irrigation system. This should water the soil at the outer half of the circle formed by the drip line^[47] to encourage root growth.
Independently from annual rainfall, it is recommended to water young trees at least during summer and early autumn.^[47] Once established it resists well to droughts.^{[12][25][63][64]}

Preservation

Because of their high water content, transpiration rates and consequent loss weight, for storage purposes they react as fresh fruits (not as nuts). They should be kept cool at all times including in shops when on display for sale.^[47] To preserve their freshness for a few months with no artificial refrigeration, the chestnuts can be soaked in cold water for about 20 hours immediately after harvest; after which they are dried in the shade, then layered in dry sand.^[36]
On the other hand, chestnuts behave similarly to seeds in that they produce very little ethylene, and their respiration rate is low – varying between 5 and 20 mg/kg-h according to the temperature.^[7]

Pests

• The main threat to Chestnut trees comes from grey squirrels stripping its bark, from when the tree is about 8 years old and onwards through the life of the tree.^[47]
• Rabbits and wallabies can do great damage to young trees, which need guarding by some fence or by wrapping the tree trunk in sisal or other appropriate material. Deer and kangaroos can also be troublesome.^[47]
• Cattle and horses may require temporary fencing to prevent them from damaging fallen chestnuts at harvest time.^[47]
• The sulphur crested cockatoo can damage branches up to 10 mm in diameter by carrying out "beak maintenance" on young trees.^[47]
• Rosellas can also be troublesome at harvest time. ^[47]
• The larva of the polyfag moth (Phytomyza horticola)^[65] species are among those who do most damage to shoots and foliage.^[66]
• The most frequently occurring pests are the winter moth (Operophtera brumata) and the mottled umber moth (Erannis defoliaria).^[66]
• The Oak roller weevil (Attelabus nitens) causes relatively less damage by rolling up the Chestnut leaves into a barrel shape to shelter its eggs and its developing larvae. The insects swarm from the end of April to mid-June, and damage the tree's flower buds during their feeding season.^[66]
• The larvae of the Oak-leaf-mining moth, also called the Tischerid moth (Tischeria ekebladella), dugs white, see-through mines in Chestnut's leaves. It lays its eggs in the leaves between May and June. The larvae cause white spots in the leaves by chewing them from the inside.^[66]
• The Oak aphid (Myzocallis castanicola) sucks on the apex of the tree's young shoots and leaves. Native to Europe and North America, it is also active in Hungary. Leaves do not roll up, but it delays the growth of shoots and damages young plantations's graft-shoot hosts. Commercial plantations and nurseries spray pesticides during the shoots’ growth period to fight the damage.^[66] The Chestnut mosaic virus is probably transmitted by Myzocallis castanicola aphids.^[67]
• The Chestnut weevil (Curculio elephas) most often damages the Chestnut fruits. In Hungary it swarms in Chestnut orchards around August 20, particularly strongly around noon and in sunny weather. The eggs are laid into the Chestnut's cupules or around the peduncle joints. The larvae feed on the nuts and leave only nutchips and excrements within. While the chestnuts ripen, the larvae retreat into the ground after having chewed their way out of the nuts. On the following July they will turn into pupas.
  The larvae of the Chestnut weevil can only chew their way out of a fallen nut. So breeding occurs mostly where chestnuts lie on the ground for a sufficient length of time, or where the trees produce many small fruits which remain behind at the harvest. Timing the harvests to pick up the chestnuts as soon as they fall, reduces the numbers of the overwintering larvae. Regular soil work is also unfavourable to its life habits of this pest. Small Chestnut grafts are sprayed with chemicals. A warm aerosol-based protection has been developed for older trees, by Sifter and Bürgés in 1971.
  It is not recommended to plant Chestnut orchards beside Turkey Oak forests, because both trees are susceptible to the Chestnut weevil (who also uses the Turkey Oak acorn to develop) and the Turkey Oak trees can pass it on to the Chestnut trees.^[66]
• In Hungary, the most common moth threatening Chestnut trees is the acorn moth (Laspeyreisa splendana) and its subspecies. Its grayish-yellow larvae cause similar damage to that of the Chestnut weevil, but they moreover spin characteristic webs among the nutchips and larvae's excrements. This moth causes about 5-41% of the damage that occurs in western Hungaria's Chestnut plantations. Plantations need regular protection against these moths whose occurrence does not decrease.^[66]
• In New Zealand the grass grub beetle eats the soft new season foliage of Chestnut trees. They can entirely strip a young tree, in the late spring when they fly at dusk, often in huge numbers.^[11]

Diseases

• The Chestnut blight fungus Cryphonectria parasitica (formerly Endothia parasitica) affects Chestnut trees. The Eastern Asian species have co-evolved with this disease and are moderately to very resistant to it, while the European and North American species, not having been exposed to it in the past, have little or no resistance.^[12]
  Early in the 20th century, Chestnut blight destroyed about 4 billion American Chestnut trees^[42], and reduced the most important tree throughout the east coast to insignificant presence. The American chinkapins are also very susceptible to Chestnut blight. The European and West Asian Chestnuts are susceptible, but less so than the American species.^[12]
  The resistant species (particularly Japanese Chestnut and Chinese Chestnut but also Seguin's Chestnut and Henry's Chestnut) have been used in breeding programs in the US to create hybrids with the American Chestnut that are also disease-resistant.^[12]
  The bark miner Spulerina simploniella (Lepidoptera: Gracilariidae) was found in intensively managed Chestnut coppices in Greece, but not in Chestnut orchards. The insect's larvae (and the rain) may be agents in the spreading of the disease. They mine under the thin periderm of young trees up to 10 years old, while the stem bark is still smooth. Rain during the pupation period (approximately covering the last week of May and first two weeks of June), and the actions of the larvae, may collude for conidiospores to come into contact with the freshly exposed phloem, and thus cause cankers.^[68]
• "Ink disease" also appears in a number of other plants. The disease attacks the phloem tissue and the cambium of the roots and root collars about 10-20 centimeters above ground. Wet rot settles in as a result.
  It was named after the ink-black color of the tannic acid becoming oxygenated (oxydised) after seeping out, but that symptom is not a characteristic of the disease. The same ink-black colour can appear following other types of decays and mechanical injuries that make liquids seep through: these liquids can also oxydise after contact with air. Moreover, with some phytophtoric diseases, no tannic acid is generated.
  With the ink disease, the leaves turn yellow and later fall down; the fruits remain small, and the nuts prematurely drop out of the burrs. These dry and remain onto the trees throughout winter time. In acute cases, root decay make the trees dry out and wither away.^[66]
• "Sudden Oak death", or phytophtora disease, is the longest-known Chestnut-tree disease leading to tree death. Of the two main pathogens for this disease, the one in European Chestnuts is since 1971 known to be Phytophtora cambivora. Phytophtora cinnamoni was discovered in Chestnut trees in the United States in 1932. Both trigger similar symptoms. Since then, it has also been proved to occur in most European Chestnut-growing countries. It is difficult to differentiate between the two latter pathogens. Chemicals seem of little effectiveness. Many countries impose strict prophylactic rules to preserve against the spread of the disease.^[66]
• Melanconis modonia is one of the pathogens that can infect trees through injuries and induce Chestnut trees' "bark death". It was first reported in Hungary by Hausz in 1972. The damage is of little consequence in older or stronger trees, but it affects saplings's graftings in nurseries. Coryneum perniciosum, one of the two conidium-like side forms of this fungus, occurs on all decayed, ligneous parts of a Chestnut tree. The symptoms of infection on young smooth trunks is similar that with the Chestnut blight fungus Cryphonectria. For this reason it has persistently been wrongly thought of as the pathogen for the "ink disease". With Melanconis the bark sinks in and takes on brownish-red tones, with black lentil-like multicell conidium bodies and black cone-like stromas breaking through the bark. But unlike with Cryphonectria there are no orange-colored fruiting bodies. Prevention primarily includes keeping the tree in good shape; some further protections against Cryphonectria also help pretenting bark-death caused by Melanconis. ^[66]
• The Chestnut mosaic virus is probably transmitted by the Oak aphid Myzocallis castanicola.^[67]
• Root rot is brought by the fungus Armillaria mellia. When planting Castanea, recently cleared land is best avoided to help resist this fungus.^[47] The disease is more prevalent on heavier and poorly-drained soil types. ^[11]
• Leaf spot is the most common disease for Chestnut trees (Mycosphaerella maculiformis). It is known as cylindrosporium leaf spot disease, after its summer conidium form Cylindrosporium castaneae. The pathogens spend the winter in the white spots of the fallen leaves. At spring time it re-infects the new leaves. In or near June, tiny white spots on the leaves appear, which grow and turn brown over time. At the end of the summer, the spots entirely cover the leaf which turns yellow. In rainy and humid weather with large temperature fluctuation, the tree loses its leaves. If August is dry and warm the infected leaves roll up, the arteries twist, and the dead leaves dry on the tree until defoliage.This recurs yearly, even as the extent of the damage varies from year to year. Some species are more resistant than others.^[66]
• Among several foliage diseases of smaller significance for European Chestnut growing, Oak mildew infects the most trees (Microsphaera alphitoides). Younger trees suffer most: their shoots become short-jointed, growth is delayed and they develop sensitivity to frostbite. In older trees, the fungus usually infects only the tip of the shoots. The pathogens hibernate in the shoots and infect the leaves from there. The fungus grows on the top of the leaves, with the appearance of a coating only in mid-summer. The infected leaves' development slows down or stops, the distance between their vessels shrink, and the vessels themselves become curly.^[66]

• Breaking the tuft provides the most common entrance for fungi spores during storage. Cyboria, the most diffuse, turns the flesh black and spongy. Other fungi are known, such as Rhizopus, Fusarium, Collectotrichum.^[7]

Uses

Culinary

The fruit can be peeled and eaten raw (almost unknown in North America), but it then can be somewhat astringent especially if the pellicle is not removed.^[69]

The other way of eating the fruit which does not involve peeling, is to roast them. Any method of cooking requires to score the fruit beforehand, else the flesh expands and the fruit explodes. Once cooked its texture is similar to a baked potato, with a delicate, sweet, nutty flavour.^[26][9][70] This method of preparation is popular in northern China where the scored chestnuts may be cooked in a tub of heated coal pebbles.

Chestnuts can be dried and milled into flour, which can then be used to prepare breads, cakes, pancakes, pastas (it is the original ingredient for "polenta"^[6], known in Corsica as "pulenda"), used as thickener for stews, soups, sauces..., . The flour can be light beige like that from Castagniccia, or darker in other regions.^[35] It is a good solution for long storage of a nutritious food.^[19] Chestnut bread keeps fresh for as long as two weeks.^[6]

A fine granular sugar can be obtained from the fermentation of the juice^[6][71], as well as a beer; and the roasted fruit provides a coffee substitute.^[71] Parmentier, who among other things was a famous potato promoter, extracted sugar from chestnuts and sent a chestnut sugarloaf of several pounds' weight to the Academy of Lyon. ^[72] The continental blockade following shortly after (1806-1814) increased the research into developing chestnuts as a source of sugar, but Napoleon chose beets instead.^[14]

The nuts can also be eaten candied, boiled, steamed, grilled, roasted or fried (fritters), in sweet or savoury recipes.^[6] They can be used to stuff vegetables, poultry, fowl and other edibles.^[18] They are available fresh, dried, ground, canned (whole or in puree).

Candied chestnuts (whole chestnuts candied in sugar syrup, then iced^[40]) are sold under the French name marrons glacés or Turkish name kestane şekeri ("sugared chestnuts"). They appeared in France in the 16th century. Towards the end of 19th century, Lyon is brought low by the collapse of the textile market, notably silk. Clément Faugier ingénieur des Ponts et Chaussées, is looking for a way to revitalize the regional economy. In 1882 at Privas, he invented the technology to make marrons glacés on an industrial scale (although a great deal of the over-twenty necessary steps from harvest to the finished product are still accomplished manually).^[18] Chestnuts are picked in autumn, and candied from the start of the following summer for the ensuing Christmas. Thus the marrons glacés eaten at Christmas are those picked the year before.^[73]

Sweet Chestnuts are not easy to peel when cold. The most efficient way to peel them is described here.^[27]
One kilogram of (untainted) chestnuts yields approximately 700g of shelled chestnuts.^[26]

Chestnuts' taste vary slightly from one to the next but is somewhat sweet and certainly unique. Chestnut-based recipes and preparations are making a comeback in Italian cuisine, as part of the trend toward rediscovery of traditional dishes and better nutrition.

Animal fodder and litter

Chestnuts are often added to animal fodder. A first soak in lime water deprives them of their bitter flavour, then they are ground and mixed with the ordinary provender. Other methods of preparation are also used. It is given to horses and cattle in Extreme-Orient^[18], to pigs in England^[18], France^[36] and other places. The leaves are not as prone to be insect-eaten as those of the Oak, and are also used for fodder.^[18]

Medicinal properties

The fruit is very nutritious, energising, remineralising, a tonic for muscles, nerves and veinous system, anti-anemic, antiseptic and stomachic. It is recommended to convalescents.^[36]

The tannin in leaves and bark makes these astringent, useful to treat bleedings, diarrhoeas etc. They are anti-inflammatory, astringent, expectorant and tonic.^[18][74][75] The leaves are harvested in June or July and can be used fresh or dried.^[18] An infusion has been used in the treatment of fevers and ague, but are mainly employed for their efficacy in treating convulsive coughs such as whooping cough and other irritable conditions of the respiratory system.^[18][74] The leaves can also be used in the treatment of rheumatism, to ease lower back pains and to relieve stiff muscles and joints.^[76] A decoction is a useful gargle for treating sore throats.^[76] The bark has been used as antidiarrheic because of the tannins.^[36]

The plant is used in Bach flower remedies - the keywords for prescribing it are 'Extreme mental anguish', 'Hopelessness' and 'Despair'[209].^[56]

Wood extract (mixed at a 1:2 to 1:6 ratio with sugar) is used as a natural agent for the prevention and cure of diarrhoea in animals.^[77]

Timber

Chestnut is of the same family as Oak, and likewise its wood contains much tannins.^[30] This renders the wood very durable,^[30] gives it excellent natural outdoor resistance,^[30][78] and saves the need for other protection treatment. It also corrodes iron rapidly although copper, brass or stainless metals are not affected.^[78]

Chestnut timber is decorative: light brown in colour, it is sometimes confused with Oak wood.^[78] Both woods' textures are also similar.^[30] When in a growing stage thus with very little sap wood, a Chestnut tree contains more timber of a durable quality than an Oak of the same dimensions. Young Chestnut wood has proved more durable than Oak for woodwork that has to be partly in the ground, such as stakes and fences.^[18]

After most growth is achieved, Chestnut timber tends to split and warp more the older it is harvested; it becomes neither as hard nor quite as strong as Oak wood.^[18][30][78] The American Chestnut Castanea dentata served as an important source of lumber, because that species has long unbranched trunks.^[8] In England it was nevertheless formerly used indiscriminately with Oak for the construction of houses, mill-work and household furniture.^[18] It grows so freely in that country, that it was long considered a true native – partly because the roof of Westminster Hall and the Parliament House of Edinburgh were mistakenly thought of as Chestnut wood. But Chestnut wood loses much of its durability when grown beyond fifty years old, and despite the local Chestnut's quick growth rate it remains that the timber used for these two buildings is considerably larger than a 50-year-old Chestnut's girth. It has been now proved that they are of Durmast Oak, which grain and colour closely resembles that of Chestnut.^[18]

It is therefore uncommon to find large pieces of Chestnut wood in building structures, but it has nevertheless always been highly-valued for small outdoor furniture pieces where durability is important, such as fencing and wooden outdoor cladding ('shingles') for covering buildings.^[78], pit-props^[18] In Italy, it is also used to make barrels used for aging balsamic vinegar. Of note the famous eighteenth century's "berles" in the French Cévennes: cupboards cut directly from the hollowed trunk.^[79]

Coppicing

Most wood production is done by coppice systems, cut on a 12-year rotation to provide small timber which does not split as badly as large logs.^[43] In southern England (particularly in Kent), Sweet Chestnut has traditionally been grown as coppices, being re-cut every ten years or so on rotation for poles, used for firewood, fencing (fence posts and chestnut paling) and especially to support the strings up which hops are grown.

Fuel

Dry Chestnut firewood is best burned in a closed log-burner because of its tendency to spit on an open fire.^[78]

Sustainable forest management|Forestry]]

An excellent soil-enriching understorey^[18] in Pine forests^[12][56] Sustainable forest management incorporates more mixed plantings of proven efficiency, as opposite to monosylviculture. A study presented in 1997 has evaluated positively the potential increase in productivity with mixed stands and plantations, comparatively to plots of only one species. The relative yield total values of the mixed plantings steadily increase with time. It has shown that Castanea sativa responds well to competitive pressure from Pseudotsuga menziesii, the latter also showing a higher productivity.^[80] Another study with Castanea dentata seedlings in Ohio concluded that reforestation efforts with Castanea is best achieved by planting Castanea in places with little or no arboreous land cover, because of the need for light.^[62]

Wildlife

The tree is noted for attracting wildlife. The nuts are an important food for jays, pigeons, wild boar and squirrels. Several insects, notably the Chestnut weevil Curculio elephas, also feed on the seeds.^[12] The leaves are used as a food plant by the larvae of some Lepidoptera species (butterflies and moths); see list of Lepidoptera that feed on chestnut trees. American and Chinese chinquapins (Castanea pumila and Castanea henryi) have very small nuts that are an important source of food for wildlife.^[8]

Other uses

Chestnut wood is a useful source of natural tannin, used for tanning leather before the introduction of synthetic tannins.^[43] On a 10% moisture basis, the bark contains 6.8% tannin and the wood 13.4%.^[54] The bark imparts a dark colour to the tannin, and has a higher sugar content which increases the percentage of soluble non-tans, or impurities, in the extract; so it was not employed in this use.^[81]
Chestnut tannin has a naturally low pH value, relatively low salts content and a high acids content. It is one of the pyrogallol class of tannins. As it tends to give a reddish tone to the leather, it is most often used in combination with quebracho, mimosa, myrabolans, and valonia. ^[81]
The wood seems to reach its highest tannin content after the trees reach 30 years old. The southern European Chestnut wood usually contains at least 10 to 13% more tannin when not higher, than Chestnut trees in northern climates. Today the largest producer of Chestnut wood extract for tanning is Italy. ^[81]

Fabric can be starched with chestnut meal^[18]

Linen cloth can be whitened with chestnut meal^[18]

The leaves and the skins (husk and pellicle) of the fruits provide a hair shampoo.^[36][74]

Artistic references

• The jazz standard "April in Paris" begins, "April in Paris / Chestnuts in blossom."
• In the Polish film, Ashes and Diamonds, two characters reminisce about the Chestnut trees that once lined a famous boulevard destroyed in the Warsaw Uprising.
• "The Christmas Song" begins with the phrase "Chestnuts roasting on an open fire." Nat King Cole's hit recording is now a Christmas standard.
• In the movie Howards End, Mrs. Ruth Wilcox (Vanessa Redgrave) tells of her childhood home, where superstitious farmers would place pigs' teeth in the bark of the Chestnut trees and then chew on this bark to ease toothaches.
• In the novel Jane Eyre, a Chestnut tree outside of Thornfield Hall is broken in two by lightning. This foreshadows the break-up of Rochester and Jane's marriage.
• The opening lines of Longfellow's poem The Village Blacksmith are "Under a spreading Chestnut-tree / the village smithy stands." This famous reference is much remarked upon by those involved in projects to return the American Chestnut to the wild.
• In George Orwell's 1984 the Chestnut tree is used in poems recited throughout, referring to nature, modern life, and lies as in the saying; 'that old chestnut'.

Famous Chestnut trees

• Chestnut Tree of One Hundred Horses on Mount Etna. 57.9 m (190 ft) circumference in 1780. (64 metres circumference in 1883^[82][58]
• Tortworth Chestnut. 15.8 metres (52 feet) circumference in 1776, when it was described as "the largest tree in England"^[83]
• Sacred Chestnut of Istan. 46 feet circumference, estimated to be between 800 and 1,000 years old.

References

External links

• How to Roast Chestnuts.
• How to peel chestnuts easily.
• The American Chestnut Foundation.
• Chestnut museum in the Beaumedrobie country - Joyeuse, France.
• Pictures of various Chestnut lumber and veneer.
• Picture – Autumn colours of a Chinese Chestnut tree (Castanea mollissima) with pictures of that species' leaves and flowers.
• Picture – Large Japanese Chestnut tree (Castanea crenata) in Old Lyme, Connecticut in 1876 and photographed in 2000.
• Picture - Large, old and gnarled Sweet Chestnut tree at Sheffield Park Garden.
• Tahitian Chestnut tree’s mad root system.