Chestnuts are a group of trees almost everyone has heard of but most Americans have probably never seen one. How did this come to be? While some of this is a cultural inheritance from Europe, what few people know is that North America once had more chestnuts than anywhere else on earth.
The American chestnut, Castanea dentata used to be a dominant tree across most of Eastern North America, particularly in the Appalachian mountains. The nuts were a crucial food source for both native peoples and later European migrants. High in starch, they are easily dried and preserved in a similar fashion to grains. The trunks, large, straight, and tall, were among the most useful sources of timber and many older homes in the Eastern US still contain wood from this species, though little to none has been harvested in recent times.
Sadly, this magnificent tree was one of the first victims of the global transport of pathogens. A fungal blight, introduced to New York in 1904, spread like wildfire through the chestnut forests, killing the above-ground portion of virtually every tree. Surprisingly, the blight never reached the West Coast, and there are a small number of American chestnuts that can be seen in a few areas, brought by migrants as a source of food. I have not seen any locally, but there are some near Chico, the Bay area, and in the Sierra Nevada.
Today, the most common species in California is the European chestnut, C. sativa. It is also very susceptible to the blight, but for whatever reason is the most commonly used for nut production. Native to the mediterranean, it seems to grow well here. There are also several Asian species, which have the best blight resistance, but they are rarely grown in our area.
Issues of blight aside, chestnuts are rarely used as urban trees. Their spiny burs are simply too much of a nuisance for most land managers to tolerate. However, they are large, beautiful shade trees that produce an abundant, starchy food source, so they could have their use here and there. On large properties, away from paths, the burs should not be much of an issue, so this could be a useful tree for a forest garden or other edible landscape.
Looking to the future, perhaps spineless varieties could be developed. There are notes from breeding efforts in decades past that allude to such trees, but I have not found any recent work on this topic. Additionally, after over 100 years of effort researchers have finally produced a fully resistant American chestnut variety. The USDA is expected to allow sale of this tree to the public soon, so it could also be trialed in our area.
The American chestnut, Castanea dentata used to be a dominant tree across most of Eastern North America, particularly in the Appalachian mountains. The nuts were a crucial food source for both native peoples and later European migrants. High in starch, they are easily dried and preserved in a similar fashion to grains. The trunks, large, straight, and tall, were among the most useful sources of timber and many older homes in the Eastern US still contain wood from this species, though little to none has been harvested in recent times.
Sadly, this magnificent tree was one of the first victims of the global transport of pathogens. A fungal blight, introduced to New York in 1904, spread like wildfire through the chestnut forests, killing the above-ground portion of virtually every tree. Surprisingly, the blight never reached the West Coast, and there are a small number of American chestnuts that can be seen in a few areas, brought by migrants as a source of food. I have not seen any locally, but there are some near Chico, the Bay area, and in the Sierra Nevada.
Today, the most common species in California is the European chestnut, C. sativa. It is also very susceptible to the blight, but for whatever reason is the most commonly used for nut production. Native to the mediterranean, it seems to grow well here. There are also several Asian species, which have the best blight resistance, but they are rarely grown in our area.
Issues of blight aside, chestnuts are rarely used as urban trees. Their spiny burs are simply too much of a nuisance for most land managers to tolerate. However, they are large, beautiful shade trees that produce an abundant, starchy food source, so they could have their use here and there. On large properties, away from paths, the burs should not be much of an issue, so this could be a useful tree for a forest garden or other edible landscape.
Looking to the future, perhaps spineless varieties could be developed. There are notes from breeding efforts in decades past that allude to such trees, but I have not found any recent work on this topic. Additionally, after over 100 years of effort researchers have finally produced a fully resistant American chestnut variety. The USDA is expected to allow sale of this tree to the public soon, so it could also be trialed in our area.