Tree a Week: Chestnut

Characteristics and Fun Facts

  • The chestnuts are a group of eight or nine species of deciduous trees and shrubs in the genusCastanea, and in the beech family Fagaceae.
  • They are native to temperate regions of the Northern Hemisphere, the four most commonly known species groups are American, European, Chinese, and Japanese chestnuts.
  • Fully grown chestnuts usually reach heights of 16m – 25m tall, however the size of chestnut trees can differ greatly depending on species; Japanese chestnut (C. crenata) at 10 m average; followed by the Chinese chestnut (C. mollissima) at about 15 m, then the European chestnut (C. sativa) around 30 m to the giant of past American forests, C. dentata that could reach 60 m.
  • Most chestnut tree types begin to produce nuts after they are 3 to 7 years old and can live for up to 800 years.
  • Chestnut trees respond greatly to coppicing and produces a good crop of tannin-rich wood every 12 to 30 years.
  • The sweet chestnut is believed to be introduced to the British Isles by the Romans where the fruit were used to produce bread to feed troops and to provide fodder for their horses.
  • They require little maintenance, pruning or fertilization. However, some weather conditions can make chestnuts vulnerable to fungal infections.
European distribution map of the chestnut tree.

Chestnut Blight Disease

This is the most destructive of all known, chestnut diseases. There are no easy methods to cure a chestnut blight infection and most affected chestnuts eventually die. Also known as Bark Disease, it is caused by the Cryphonectria fungus. The fungus enters the tree’s bark through wounded sites on the bark’s surface. Chestnuts are sturdy, pest-resistant trees and very few chestnut diseases can cause large-scale damage.

Trademark signs of bark disease.
Image of how magnificent American chestnut trees were before being decimated by the blight in the 1950s.


  • Tannin makes the young growing wood durable and resistant to outdoor use, and is thus suitable for posts, fencing or stakes.
  • The light-coloured, dark and strong wood is used in making furniture, barrels and roof beams.
  • The cooked nuts can be used for stuffing poultry, in nut roasts, confections, puddings, desserts and cakes.
  • Chestnuts are an excellent source of healthy starch and make an excellent substitute for flour, bread, cereal substitute, coffee substitute, thickener in soups and other cookery uses, as well as for fattening stock.
  • A sugar can be extracted from them. The Corsican variety of polenta (called pulenta) is made with sweet chestnut flour.
  • Pietra, a local variety of Corsican beer also uses chestnuts.

Other uses

  • In parts of Europe, the nuts were once used to make starch for laundry use and to whiten linen.
  • The chestnut leaf infusion has been used as a remedy for whooping cough and to cure other conditions of the respiratory systems. It has also been used to treat diarrhoea, rheumatism, to ease lower back pains and to relieve stiff muscles and joints.
  • A shampoo can be made from an infusion of leaves and husks.



Leaves: Leaves are a fresh green in colour, darker on the top than the bottom. They are oval or lance-shaped and edged by widely separated teeth.

Flowers: The flowers of the chestnut tree are long, drooping catkins that appear on the trees in spring. Each tree bears both male and female flowers, but they cannot self-pollinate.

Fruits: The fruit is contained in a spiny (very sharp) cupule 5–11 cm in diameter, also called “bur” or “burr“. The burrs are often paired or clustered on the branch and contain one to seven nuts according to the different speciesvarieties, and cultivars. Around the time the fruits reach maturity, the burrs turn yellow-brown and split open. 

  • IMPORTANT. Chestnuts should not be confused with horse chestnuts, in the genus Aesculus they are named for producing nuts of similar appearance that are mildly poisonous to humans.


Chestnuts are typically harvested mid-September through November and are one of the easiest nut varieties to harvest and prepare for storage.


  • Beat the Squirrels: Try to gather the chestnuts as soon as they fall to the ground. It will preserve the quality of the nuts and minimise loss to squirrels .
  • Look for Open Burrs: When the chestnut is mature, the burrs will open, and that’s when you want to remove the husks with your feet or wear thick gloves.  Look for shells that are smooth, glossy and heavy as these are often the tastiest. Discard any with wormholes or other signs of damage.
  • Don’t Shell Until Needed: Chestnuts will dry out within a week of being removed from the shell. Keep them fresh by shelling them right before you’re ready to use them. In-shell chestnuts will keep in the refrigerator for a month or in the freezer for a year.
  • Listen for the Rattle: Chestnuts that are in the shell dry out and shrink as they age. Test the freshness of chestnuts by shaking them. If you hear rattling inside the shell, they may be too dry to eat.

Storing and Cooking

At room temperature, fresh nuts stay good for a week and will reach their sweetest after 3 days if left in a single layer where air can circulate. But after this the nut skin starts getting hard. Roasting chestnuts is a very popular method but can also be microwaved, open fire roasted, braised or boiled. Check the video below for easy chestnut peeling…

Chikara has tried the method, it doesn’t work as well as it does in the video, but this may be due to the differences in the variety and quality. It could also be a result of clever editing…

Give it a go when the season starts, and let me know how you get on.

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If you want to know more about trees, particularly in the context of creating a forest garden, this book by Martin Crawford is worth checking out. It’s pretty affordable for a thick comprehensive book full of quality photographs and a lifetime’s worth of research and expertise from a man who has been at the forefront of forest gardening for the last 20 years.

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