Available Books
Order Books
About Frank

Uses of Wild Plants - American Chestnut

What reviewers say about
Uses of Wild Plants

Hortideas. Sept – Oct 2007

Excerpts of
Uses of Wild Plants

Castanea dentata / American Chestnut
Portulaca oleracea / Purslane
Urtica dioica / Stinging Nettle

Castanea dentata / American Chestnut

Excerpt from: Uses of Wild Plants

Castanea dentata / American Chestnut
East & locally elsewhere Fagaceae

Once there were billions of Chestnut trees in the eastern hardwood forest, this single species making up almost a quarter of all the trees, yet most people in the east today have never even seen a mature American Chestnut tree. This is because they simply no longer exist over most of their former range.  Some time around 1904 the fungus disease Chestnut Blight or Cryphonectria (formerly Endothia) parasitica was introduced on imported Asian Chestnuts.  The native trees had no resistance to this hitherto unknown disease and in the 1920's and 30's it infected almost all of the trees in its range.

The trees don't always die from the disease, many roots survive to this day, sending up suckers that grow vigorously to a height of 20 feet and a diameter of four inches, but eventually the disease kills the tops (some trees even produce a few fruits before succumbing).  The persistent roots then start all over again, by sending up new shoots.

Though mature trees are rare in its native range, the plant is in no way endangered. Not only do roots persist, but trees planted on the West Coast live on and a few groves even survive in the east.  Recent developments even bring hope that the disease may be overcome and the trees will return.

Ever since the Blight first came to North America people have been searching for naturally resistant American Chestnuts and have also crossed them with blight resistant Asian Chestnuts.  There have been many false hopes raised in the past, but disease resistant strains may now finally be appearing.

Perhaps of even greater significance are reports that the fungus itself is being attacked by a virus which weakens it to the point where it no longer kills the tree, which then recovers from the infection. This happened in Europe and helped save the commercially important Chestnut forests there.  Injections of this weakened fungus have been used experimentally in this country and have apparently helped trees to survive. 

In the near future the American Chestnut may once again take its place in the eastern forest.  Its many uses once made it the single most important and useful tree species in North America.  

Nutrients: Chestnuts have been a staple food for people in Asia, Europe, North America and North Africa.  Unlike most common nuts they don't have much protein or fat, but contain about 40% carbohydrate, which gives them a food value of about 1000 calories per pound. They are also rich in iron, phosphorus and potassium.

Food:  Mature trees fruit abundantly and are said to produce more food than an equivalent area of wheat.  They were an important food for Native Americans and the first white settlers.

Gathering:  Though there are precious few American Chestnuts to be found in the east, there is the Chinkapins  and the introduced Asian species.  American Chestnuts have been planted on the west coast and these continue to thrive, happily out of the range of the disease.

Remove the spiny husks from the nuts as you collect them, by rolling them under your feet.  Before the Blight appeared the main problem for Chestnut gatherers and growers was the Chestnut Weevil.  The larvae of this insect destroy the kernels of mature nuts, so the nuts must be gathered as soon as they are ripe and frozen or heat-treated to kill the eggs (a microwave oven does this effectively).  The nuts can then be dried or frozen (best) for later use.

Preparation:  Chestnuts can be eaten raw, but they aren’t very good and frequently cause gas.  They are excellent when baked or roasted, as this turns some of the starch into sugar and gives them a sweet flavor.  Traditionally they are roasted in the hot ashes of a fire. You puncture the leathery skins of all but one nut and put them in the ashes to bake.  In theory the unpunctured nut is supposed to burst when they are all cooked, though this doesn't always work, so sample one occasionally until they are cooked.  You can also boil them or bake in an oven at 400 degrees for 20 minutes (puncture them).

In Europe Chestnuts were commonly made into flour for baking bread and cakes (these were often wrapped in Chestnut leaves for baking.) They were also used for making a kind of porridge, usually mixed half-and-half with wheat or corn meal.  They have also been roasted as a coffee substitute.

Wood: In colonial times the trees were very important for their attractive and rot resistant wood.  This splits easily along the grain to make wide planks, which was a significant consideration before power saws.  It is soft enough to be worked with quite simple tools and was available in very large pieces.  It is also very durable when in contact with water.  Fallen trunks are sometimes still sound after lying on the ground for forty years.

Chestnut was considered as good as Oak (Quercus) for building construction, split rail fences, shingles, shakes, telephone poles, railroad ties, fence posts, bridge timbers and pilings.  It is a little too soft to be really prized for cabinetmaking, though it was often used.

In Europe the Chestnut is frequently coppiced to provide the small diameter poles so necessary in peasant farming.  It was also widely used for split basket weaving.  The bark was used for tanning leather. 

Fences:  In Britain coppiced Chestnut poles were commonly used for making pale fencing or palings; indeed this was the sole purpose of many plantings.  The poles were harvested when about 5 ‑ 6 inches in diameter and cut into sections the height of the fence required.  They were then split lengthwise into pales (Cloven strips of wood about 2 X 1 inches in thickness.)  These were bound tightly into bundles to keep them straight and left to season. The seasoned pales were made up into fencing on a special apparatus consisting of three pairs of galvanized wires.  The pales were laid individually between the pairs of wires about an inch apart and the wires were then twisted to hold them securely.  Pale fencing can also be made on site.  This fencing is light, durable, rolls up easily and is strong enough to resist livestock and humans (it is also awkward to climb over). 

This fencing was once commonly made in Appalachia for use as snow fencing, to hold snow and prevent it drifting.  This craft could be a valuable source of income for omesteaders with coppiced chestnut, as it needs little equipment or skill to make.

Firewood:  Chestnut wood is also good firewood, though rarely available in quantity today.  The thrifty Europeans bound waste wood and prunings into faggots for fuel.  Chestnut coppice is a good way to grow firewood (see Populus for more on fuel wood coppice).  In colonial America Chestnut was converted into charcoal for the fledgling steel industry.

Animal Food.  Chestnuts were very important food for wildlife and livestock.

Crop Use: In Southern Europe a peasant economy grew up around the indigenous Chestnut forests and created a symbiotic relationship between humans and trees that lasted for over a thousand years.  The finely tuned, self sustaining forest agriculture that developed was a model of agro-forestry, and could teach us a lot about ecologically sustainable agriculture.  Sadly it has declined in this century.

The European forest farmers gradually replaced the wild Chestnut trees with grafted varieties, creating large forests of select cultivars.  To replace a tree that was past its prime they would plant a young grafted sapling nearby and when the sapling was well established they would fell the old tree while the wood was still useful, leaving the sapling room to mature.  The nuts were a staple human food, while livestock foraged for the nuts overlooked by human harvesters.  The animals also kept the forest open and more accessible by eating low growing vegetation.  Chestnut weevils were kept in check by chickens foraging under the trees.  The wood of mature trees was used as lumber, while smaller branches were bound into faggots for fuel.  Dead leaves were used as bedding for humans and litter for livestock (their high tannin content makes them toxic to most insects).  The soiled litter was finally used as fertilizer for gardens.

Propagation:  These trees are easily grown from ripe seed, planted two inches deep in autumn.  They must be kept moist to preserve viability and must be protected from rodents (which will eat them).  The seedlings are planted out in a nursery bed after a year and into their permanent home three years later (they have a deep taproot so take care when moving them).  Under ideal growing conditions they grow very rapidly, often adding an inch to their diameter annually and producing useful lumber in only 50 years.  Mature Chestnut trees may grow to 100 feet in height and four feet in diameter.  They start bearing fruit in 7 ‑ 10 years, or even earlier with some cultivars.

Wild nuts are usually fairly good, but cultivated trees are grafted for improved yield, quality and earlier bearing.  Over the centuries many cultivars of Chestnut have been bred (especially in Europe), with special varieties for animal feed, desserts and flour.

Coppice:  Coppiced Chestnut can be grown by itself, or as a productive understory beneath larger fruit or lumber producing trees (known in England as Coppice with standards).  It is possible to grow Chestnuts as coppice even with the blight still around. See Hazel (Corylus) for more on coppicing. 

Related Species: After the near total loss of the American Chestnut, a number of exotic relatives have been widely planted in the east, including:
C. crenata Japanese Chestnut
C. molissima Chinese Chestnut
These species are not really wild trees in North America, though they are often planted for their excellent nuts.  The Japanese species is the most blight resistant and very precocious, sometimes fruiting when only five years old.