Sweet chestnut - Castanea sativa
- The Foraging Course Company
- Feb 14
- 3 min read
Updated: Feb 18
Edible tree - novice Season - present all year. Flowers: early summer. Leaves: spring to autumn. Fruits: late autumn Common names Sweet chestnut, chestnut, European chestnut, Spanish chestnut
Scientific name meaning: The Greek town of Castonis is the origin of the genus name of chestnut trees. Sativa comes from the Latin Sativus, meaning that which is sown
Habitat  Found in woodland, parkland and in gardens. It is native to southern Europe, northern Africa and parts of Asia. The Romans introduced it to Britain where it has naturalised. |
Overall structure  Sweet chestnut can reach 36m and forms an oval-shaped crown when mature. It has dense foliage and broad branches. It can be long-lived with a large trunk girth. |
Leaves  The leaves are lance shaped, dark green, glossy and have pinnate veins. The edge of the leaf has widely spaced teeth that terminate in a hairy spike - this gives them the appearance of being prickly, which they are not. They are arranged in alternately in clusters. |
Trunk  The bark of the sweet chestnut starts of smooth and grey-brown. As it gets to several decades old, the bark from a criss-crossed ridge texture - often resembling a lattice. At about 60 years old, the trunk starts to twist causing these ridges to spiral around the tree. This pattern makes the tree easy to identify in winter. |
Flowers  Long catkin-like flowers appear in summer. The female flowers are located at the base of these catkins. As they mature, the male flowers turn yellow. The remains of the male flowers are sometimes trapped by the forming fruits that follow flowering. |
Fruits  The fruits form in husks that are densely covered in spines. These turn brown and drop to the floor when the nut inside is ripe. The nut itself has a notch on the top and often a flat side where it has been pressed against other nuts within the sheath. The fruits are ripe in late autumn and fall during high winds, which helps to split open the spiky husk. |
Possible lookalikes  Horse chestnut (Aesculus hippocastanum), pictured, is often confused with sweet chestnut. However, the leaves are palmately compound, the flowers are on erect racemes (sometimes called candles), the nuts lack a notch and the seed husks are much less spiky. Horse chestnut nuts (conkers) are toxic without thorough processing. |
Use as a food The nuts are the only part that is eaten and they should be cooked. They ripen in late autumn. They can be roasted or boiled, and have a sweet flavour. They can be dried and ground into a flour Use in herbal medicine and medicine Sweet chestnut has been used to treat rheumatism, back pain, and diarrhoea. It has also been used to clear phlegm
If you are suffering from any ailment or need medical advice, please see your General Practitioner.
Hazards None known
Other uses Popular as a fencing material, sweet chestnut is useful for other forms of carpentry as it is hard and light. Shampoos have been made from the leaves and nut shells, while tannins has been obtained from the bark Importance to other species The leaves and nuts provide food for several species of moth larvae. Red squirrels also eat the nuts once they are free of the husks. Some fungi form mycorrhizal relationships with sweet chestnut
Always stay safe when foraging. You need to be 100% sure of your identification, 100% sure that your foraged item is edible, and 100% sure that you are not allergic to it (it is good practice to always try a small amount of any new food you are consuming). If in doubt, leave it out!