Learn everything there is to know about the American Chestnut Tree, its various characteristics, where it usually grows, its diseases and the things we get from the tree.
The eastern forest in North America is missing a vital component of its forest ecosystem. Native plants and animals of North America suffer from the horrific loss of the American chestnut tree. This superstar of a tree didn’t just grow a delicious, classic, and wonderfully edible nut, it was once the most important tree species on the continent.
Chestnut lumber was once one of the greatest materials to use in house construction. A young tree would be planted in rows along city streets, and the native chestnut would be a common snack to encounter on an afternoon walk.
Unfortunately, the American chestnut is not a blight-resistant tree. Fungal blight has caused this tree variety to become functionally extinct, but thanks to backcross breeding, a transgenic tree is being bred to become part of disease-resistant varieties.
To learn more about a huge variety of different trees, check 101 Types of Trees from around the world.
Curious about different types of chestnut trees? We’ve got you covered with 4 Types of Chestnut Trees.
Related: All types of trees
The American chestnut tree is a species that is usually referred to in past tense. A deciduous tree part of the beech family, along with the beech and oak tree, Castanea dentata was at one time the most important and prevalent tree in North America. American chestnut wood was once considered the finest chestnut varietal in the world, and it exceeded 4 billion in numbers.
American chestnuts are fast-growing, and long-living trees. But their quickness to height-dom by no means affects the strength of their trunks, as they are extremely sturdy and large. Growing to heights of over 30 meters, with a trunk diameter of 3 meters, the American chestnut tree was something to behold. The tallest one on record right now is 35 meters in height.
The American chestnut tree received its scientific name, Castanea dentata, due to the fact that its leaf margins have widely spaced teeth. Dentata translates to “tooth” in Latin.
Are American Chestnut Trees Extinct?
There are not many conversations that occur about the American chestnut tree that excludes the topic of the chestnut blight fungus. The story of the chestnut blight is a long and depressing one, and it all started in the early 20th century.
A disease called Asian bark fungus from the fungi species cryphonectria parasitica (formerly known as endothia parasitica) was introduced to North America in 1905 through importation of Chinese chestnut trees (castanea mollissima). Chinese chestnuts, since they had already been surrounded by the fungus, were almost entirely resistant to infection. The same cannot be said for the American chestnut tree.
The first notice of infection occurred in the Bronx zoo, where chief forester Hermann Merkel, estimated that the blight was likely to infect near 100% of the American chestnut trees in the borough. His estimations were unfortunately correct, and the estimation could be applied to all species in North America.
The Chinese chestnut tree was probably thankful for its blight resistance around this time. All of its neighbors would be developing cankers that would ultimately lead to their demise. A canker on a tree is basically like having an open wound. The wound would remain open, making it vulnerable to all sorts of other fungal infections and parasites.
A tree that once made up 30% of all hardwoods in Pennsylvania, accounted for 25% of all trees in the Appalachian Mountains hardwood forest, and numbered over 4 billion in all of North America, was completely decimated in the first half of the 20th century.
Once an American chestnut tree has died, the root system does remain intact. New shoots are able to sprout from the dead trunk, but the stump sprouts are unable to grow past 6 meters before the blight infection takes hold once more, and kills the tree. For this reason, the American chestnut tree is classified as functionally extinct.
Not only is this devastating for the tree species, its commercial value, and impact on its forest community, it is also devastating for a number of insect and animal species that have heavily relied on the foliage and fruit of the American chestnut.
In North America, there are over 60 species that feed on different aspects of the American chestnut tree, 7 of those species eat their foliage strictly. Of the 60 species, over half of them are now completely extinct.
What do American Chestnut Trees Look Like?
This impressive and large species of chestnut tree grows to be an average of 30 meters tall, with a trunk diameter of 3 meters. This makes for a rather sturdy tree. They possess a woody taproot system and sport an extremely reaching impressive canopy.
The bark of an American chestnut tree is very dark brown in color, with wide, vertical lenticels along its length. The ridges are high, and the grooves are deep. The trees’ branches are thick and extend more laterally than towards the sky.
The leaf of an American chestnut is shaped like a canoe, usually 5-8 inches long and 2-4 inches wide. The leaves themselves are a classic forest green color, with a more matte than glossy texture.
How do American Chestnut Trees Reproduce?
Like many other members of the Fagaceae family, the American chestnut tree is incompatible with self-pollination, even though they are monoecious (possessing both male flowers and female flowers). They require a nearby American chestnut to pollinate the tree or any other member of the Castanea genus.
Nut production will usually occur in a mature tree that is over 8 years old, which is rather difficult to achieve due to the chestnut blight. This tree is a prolific nut bearer, and the crops that occur in the late summer are shocking.
American chestnut trees produce flowers called catkins, which are clusters of tiny flowers with indistinct or no petals. The male catkins have small, very pale green flowers. The female characteristics are found at the base of the catkin, and those develop in the late spring to early summer.
They can be either wind pollinated by another Castanea tree nearby, or can receive a little bit of help from a trusted pollinator to get the job done. The chestnuts will develop in the late summer, and are encompassed by a green spiny burr. The burrs that encompass the nut will open and fall to the ground upon the first frost of the year.
Where do American Chestnut Trees Grow?
Before American chestnut trees were considered functionally extinct, they were prevalent in nearly every single state and province and north America.
Luckily for us, and for the tree, the chestnut blight does not agree with the climate of coastal towns. Cryphonectria parasitica relies on the hot and humid summers of the interior, and so there are certain pockets on the West Coast that still have some living American chestnuts.
There are communities of American chestnut trees that have survived in Sherwood, Oregon, Revelstoke, British Columbia. There are also other locations in the middle east of the continent that have surviving groves, but locals prefer to keep their existence a secret — to help protect the tree and the other wildlife inhabitants that rely on them. These regions include Maine, southern Ontario, Mississippi, the Appalachian Mountains, and the Ohio Valley.
Many of the surviving American chestnut trees have been either hybridized, and independently cultivated by some passionate tree lovers. Many efforts have been made to create a hybrid American chestnut tree with the Chinese chestnut tree since the Chinese chestnut is resistant to the chestnut blight infection.
This means that there is still some hope in saving this incredible tree species, even if it means that they are a genetically engineered tree.
What are Other Types of Chestnut Trees?
Luckily, there are several other species of a chestnut tree that will be able to carry on a healthy colony of trees:
- European sweet chestnut tree (Castanea sativa)
- Chinese chestnut tree (Castanea mollissima)
- Japanese chestnut tree (Castanea crenata)
- Ozark Chinquapin (Castanea ozarkensis)
- Allegheny Chinquapin (Castanea pumila subsp. ozarkensis)
Nowadays, the Chinese chestnut is the most commonly planted variety, as it is resilient to the chestnut blight.
The European chestnut is cultivated now as the primary source of chestnuts, and is used commercially. They are most easily distinguished by a difference in twigs: the European twig has downy hairs, whereas the American twig is hairless.
Both the Ozark and Allegheny Chinquapin are ancestral to the American chestnut tree.
How are/were American Chestnut Trees Used?
Food Source for Animals
There is a reason why the extinction of the American chestnut was so widely mourned, and that is because the tree was such an important resource to many different species of insects, animals, and humans alike.
The leaves of American chestnut trees contain some very valuable nutrients: magnesium, nitrogen, phosphorous, and potassium. All of the nutrients are then transferred to the soil when they fall, which helps soil health, which goes on to help the growth of other plants and animals. Not to mention all of the forest dwellers who nibble on the foliage will grow healthy and strong.
The chestnuts that fall as winter approaches are a very important food source for many species. White-tailed deer, passenger pigeons, black bears, and wild turkeys being the largest of the bunch. There are endless small mammals, birds, and insects who like to chow down on chestnuts just as much as we do!
The wood of American chestnut trees has been labeled as the greatest quality. It is incredibly strong and sturdy, and not to mention it grows almost twice as quickly as oak trees do. It is straight-grained, attractive in texture and color, and it is easily workable as well. When the American chestnut was in prosperity, the wood went towards many uses:
- paper pulp
- house construction
- telephone poles
- split-rail fences
Now that American chestnut trees are nearly impossible to find, people have taken to reclaiming wood from historic barns and fashioning it into new furniture pieces.
Food Source for Humans
Nuts from the American chestnut tree are not only edible, they are entirely delicious. When they were prevalent, they were a very common snack to find walking down a street in a metropolis. Their smell is very easily identifiable. This lovely tradition is what gave way to the Christmas carol line we all know and love; “chestnuts roasting on an open fire”.
Traditionally American chestnut bark and twigs were also made into a tea by Native American communities, in an effort to treat ailments like whooping cough, which was a severe issue at the time.
Are American chestnut trees extinct?
The American chestnut tree is currently qualified as being functionally extinct. The chestnut blight kills the trunk and branches of the tree but is unable to affect the root system. Saplings are able to sprout from the surviving root system, but once they reach a certain height the infection takes over again and kills the sapling.
Are American chestnut trees self-pollinating?
American chestnut trees, though they are monoecious (possessing both male and female characteristics) they are not able to self-pollinate. They require the pollen from a neighboring Castanea species.
How common are American chestnut trees?
At the beginning of the 20th-century American chestnut trees made up 30% of all hardwood in North America. Due to the chestnut blight, they have been completely decimated and are now considered functionally extinct. American chestnut trees are not only uncommon, they are past the point of being rare.
When do American chestnut trees bloom?
The flowers of an American chestnut tree will bloom in early spring, the fruit (chestnut) will develop in the later summer, and the nut will fall to the ground upon the first frost of the year.
How many American Chestnut trees are left?
It is difficult to say how many American chestnut trees still exist on earth. There are little pockets of tiny groves that have survived on the west coast of North America, as chestnut blight dislikes the climate in those areas.
There are small independent groves that passionate tree lovers have cultivated, and there are survivors that other communities try to keep secret to prevent further endangerment to the tree.
There is no way to know the numbers for certain.
How did the American chestnut tree die-off?
A sickness called the Asian bark fungus (cryphonectria parasitica) was brought on the importation of Chinese chestnut trees in 1905. The Chinese chestnut, since it already existed with the fungus, was resistant to the infection.
Not as much can be said for the American chestnut tree. Within 50 years, over 4 billion American chestnut trees were completely wiped out by the Asian bark fungus.
What is the difference between an American chestnut tree and a Chinese chestnut tree?
Though both parts of the same Castanea family, the American chestnut tree and Chinese chestnut tree resemble few differences. The main differing characteristic is that the Chinese chestnut tree is resilient to the chestnut blight, and the nut of the Chinese chestnut tree is covered in downy hairs, where the American chestnut is bare.
How long does it take American chestnut trees to produce fruit?
An American chestnut tree is considered sexually mature once it reaches 8 years of age. If it exists in the right conditions and has no sicknesses, it should sprout flowers in the early spring, produce a nut in the late summer, and that nut will fall to the ground upon the first frost of the year.
What is the fungus that killed off the American chestnut population?
The fungal pathogen that killed off the American chestnut population is called the Asian bark fungus, propelled by the fungi species cryphonectria parasitica.
Can you eat American chestnuts?
Not only are American chestnuts edible, but they are also completely delicious. Although the chestnuts that are available on the market today will not come from the American chestnut tree, they are probably cultivated by a very similar tree of the chestnut species, the European sweet chestnut.
Can you grow a chestnut tree from a chestnut?
Taking a fallen chestnut and trying to cultivate is the easiest way to try and grow a chestnut tree. 90% of fallen chestnuts are considered viable for germination. However, the difficulty comes from the fact that the likelihood of finding an American chestnut tree that is not only old enough to be sexually mature but is also free of chestnut blight, is extremely low.
Are chestnut trees making a comeback?
Because so many efforts are being made into hybridizing chestnut trees to make them resilient against chestnut blight, it can be said that they are making a comeback.
Cultivars are raising hybrids of Chinese chestnut trees and American chestnut trees. This is because the Chinese chestnut tree is resistant to Asian bark fungus. However, this does mean that the chestnut trees that are making a comeback, won’t be purely an American chestnut tree, but still, a blight-resistant American chestnut tree.
How long do American chestnut trees live?
When American chestnut trees were prevalent and without a decimating disease, the trees were able to live to over 100 years of age. Nowadays, it is rare to encounter a tree that can survive to sexual maturity — 8 years or more.
When a chestnut sapling attempts to sprout from the trunk of a dead chestnut tree, it is able to grow healthily for the first couple of years of life. However, once it reaches a height of about 6 meters, it will then be infected by the Asian bark fungus that killed the original tree.
How tall do American chestnut trees grow?
The American chestnut tree grows to be anywhere from 15-30 meters tall. The tallest tree on record is 35 meters tall.