A fast-growing ‘honorary native’ of Britain, sweet chestnut is a commonly coppiced species that produces durable and rot-resistant timber. We have planted three clonal seed orchards from our diverse plus tree selection, and they are due to start producing improved seed soon.

About sweet chestnut

Sweet chestnut (Castanea sativa) is generally classified as a non-indigenous but ‘honorary native’ species in Britain and Ireland. Native to southern Europe and Turkey, it has long been cultivated for its timber and its edible, starchy nuts. The species is predominantly found in the southern half of Britain and is well adapted to a wide range of site and soil conditions normally occupied by mixed broadleaved communities of oak, hazel, birch and ash. Due to its relatively recent arrival in the UK, few species are directly dependent on sweet chestnut as a host, but it does support a wide range of invertebrates, fungi and lichen that are associated with equivalent broadleaved trees.

Sweet chestnut is predicted to thrive in Britain & Ireland under future climate change scenarios but is threatened by two diseases. ‘Ink disease’ is caused by a range of soil borne fungi (Phytophthora spp.) and leads to crown reduction, early leaf fall, stem necrosis and tree death. Although widespread, ink disease does not typically cause significant tree losses unless the ground is poorly drained and compacted. Chestnut blight, caused by the fungus Cryphonectria parasitica, has caused significant regional losses in Europe since the 1930’s and was first identified in the UK in 2011. As of 2020, there have been several occurrences in southern England and regulations are in place to minimise the spread of this disease. There is evidence that the disease can be weakened by a natural virus that infects and attenuates the fungal pathogen. The phenomenon is known as hypovirulence and is already being used as a form of biological control in many European countries to minimise the impact of chestnut blight.

Sweet chestnut seed

Why sweet chestnut is important

Chestnut timber is highly versatile, naturally durable with few sapwood rings and requires no preservatives for outdoor use due to its high tannin content. Sweet chestnut is a fast-growing broadleaf that coppices very well with short rotation times – typically 12-16 years. Production stands are traditionally managed in this way to produce a diverse range of woodland products and, unlike most broadleaved species, can be used profitably from a very early age. Sweet chestnut timber is similar to oak and has been used to make furniture, barrels, poles and fencing. But, as it tends to split and warp, it is not usually used in large pieces requiring structural strength.

A 14-year old sweet chestnut coppice at Torry Hill, Kent. Demand across Europe is increasing for this timber as customers appreciate its sustainability, durability and attractive appearance

Our achievements so far

Future Trees Trust began working with sweet chestnut in 1999 when the potential of its fast growth, versatile timber and predicted response to climate change was recognised. Since then we have selected over 200 high quality plus trees across the British Isles and used genetic fingerprinting to show this collection is diverse and representative. By grafting these superior trees, we have been able to establish three clonal seed orchards (two in England and one in Ireland) that should start producing qualified seed shortly. We have also planted several clonal archive sites to conserve plus tree genetics and provide future graftwood.

Our current work

With our orchards due to start producing improved seed soon, our next steps will involve the testing of plus tree progeny. These trials will identify the lower quality individuals which can then be removed from the CSOs to improve the quality of the seed that is produced.