There are legends of a time when manna fell from the sky, and people could just pick up all the food they needed. Mature chestnut trees are pretty close to making that story a modern-day reality. Chestnuts can live for thousands of years and rain down dependable annual crops. They are magnets for wildlife, staples in several cultures, as magnificent as an oak, provide quality, durable timber, and are real epicenters of life.
Chestnuts are in the Fagaceae family, the same as oak and beech. These are the sturdy old giants of ancient forests from Maine to Turkey to Japan.
The Castanea Genus
There are several species of chestnut stretching around the temperate world with relatives in the tropics. These trees are not that well known in the United States, but they are beloved, widely used, and very common trees in many other countries. Each of these species has its own unique traits, strengths, and challenges. The members of the Castanea genus are some of the most generous and productive trees on Earth.
American Chestnut (Castanea dentata)
This tree dominated the forests of the eastern United States until it was devastated by an introduced fungus from Asia. American chestnut is a fast-growing tree with bar-none timber form. It bears small, very sweet nuts that peel easily. It is the most cold-hardy of the chestnuts. More on the American chestnut in a few pages.
Allegheny chinquapin loaded with small, sweet nuts.
Allegheny Chinquapin (Castanea pumila)
This is a shrub occasionally reaching up to 25 feet tall. It is native from Pennsylvania south through Appalachia. Chinquapins bear one nut to a burr, as opposed to the usual three found in most chestnuts. Chinquapin nuts are very small, about the size of a blueberry. They are by far the sweetest of any chestnut. Allegheny chinquapin is susceptible to chestnut blight, but it is able to send up new shoots when old ones die of blight. It can live a normal, healthy life even with blight present. Allegheny chinquapins are widely planted for turkeys, grouse, and other wildlife. They have been used in various breeding programs to add their highly sweet flavor to trees that bear bigger nuts.
Ozark Chinquapin (Castanea ozarkensis)
Botanists used to recognize this as an individual species, but they now say that it is the same as C. pumila. I’m not a botanist, but it seems obvious to me that the Ozark chinquapin is a distinct species. The trees do have similar nuts: small, sweet, and one to a burr. However, Ozark chinquapin is a forest tree growing 80 feet tall on the limestone soils of Arkansas, while Allegheny chinquapin is a medium-sized shrub of Appalachia. It seems fitting that the Allegheny chinquapin would be named pumila, meaning “dwarf.” But that name shouldn’t apply to this unique 80-foot-tall tree of the Ozark Mountains.
Ozark chinquapin is very blight-susceptible, and few have survived to this day that are not old stump sprouts dying back to the roots continuously. It has not received the attention that the American chestnut has, but there are a few people growing and breeding them. Sandra Anagnostakis of the Connecticut Agricultural Experiment Station grows many ozarkensis hybrids.
Ozark chinquapin is the only species resistant to Asian chestnut gall wasp,1 which is a significant pest. This species offers another block in the wall of Castanea’s genetic resiliency.
Ozark chinquapin nuts are 15 percent protein—a much higher ratio than found in any other species of Castanea.
European Chestnut (Castanea sativa)
Cultivated throughout Europe for thousands of years. Originating from the Mediterranean east to Iran, C. sativa was spread throughout Europe centuries ago by the Romans and other travelers who carried seeds with them. Also known as the sweet chestnut, C. sativa reigns over the continent from England to Asia Minor. It is a massive forest tree found in large, pure stands, as well as in orchards, in parks, and along the streets of Paris. There are productive orchards of European chestnut that are over 1,000 years old in Italy, Corsica, Turkey, Azerbaijan, and several other places where mountains are covered in ancient forests of chestnut. The nuts are gathered by hand in most regions, as people have done for centuries. There is one tree in Sicily that is known as the hundred-horse chestnut. Sometime in the 1500s a princess was traveling with her entourage when they were forced to take cover from a thunderstorm under this tree. Apparently she and a hundred horsemen could all fit under the massive canopy. This tree, growing at the base of Mount Etna, is estimated to be 4,000 years old. It has a trunk that measures 190 feet in circumference.
European chestnuts can produce some of the largest nuts. Italian marrones are famous for their size and flavor. European chestnuts have an enormous cultural heritage. They are found in many recipes, from candies to breads to stuffings. However, European chestnuts are very hard to peel, as the pellicle (skin under the shell) clings to the meat tenaciously. European chestnuts are also highly blight-susceptible.
Chestnut blight was accidentally introduced into Europe in the 1940s; it was believed that the trees would be wiped out just as American chestnuts were. Strangely, the disease was halted in its tracks by a wild virus. The virus has kept the blight from decimating ancient European groves, but the blight has still caused significant damage. This virus has not been as successful as in the US because we have a different strain of blight here. There are actually hundreds of strains of blight and many different viruses. Today orchards in Europe are being planted with Japanese × European hybrids for disease resistance.
Asia also is home to several unique species. There is a long tradition of using chestnuts in Korea, Japan, and China. People eat more chestnuts in Asia than anywhere else in the world. China grows more than 10 times as many chestnuts as the next country in the world, which is Korea.2
Japanese Chestnut (Castanea crenata)
Often cultivated as a spreading tree with very large nuts and good adaptability to adverse soil conditions. Japanese chestnut has the highest level of resistance to chestnut blight and phytophthora root rot (ink disease). Reportedly the nuts lack flavor, but the ones I have tasted were good. This tree is currently being used to breed super-producing trees with enormous nuts.
Chinese Chestnut (Castanea mollissima)
A tree of high variability that makes up forests and orchards, the Chinese chestnut has been the most widely planted exotic species of chestnut in the United States. The trees are highly blight-resistant. Hardiness can range quite a bit within the species. Most Chinese chestnuts in the US were brought here from sources in southern China, with a climate similar to zone 8 or 9. There are Chinese chestnuts that live at more northern latitudes all the way up into Manchuria, where it gets very cold. The Chinese chestnuts we find in the US generally lack in timber form. However, there are forests of Chinese chestnuts in China with very large trees.
Japanese chestnut in Caldwell County, North Carolina. Photo courtesy of Paul Sisco.
Seguin Chestnut (Castanea seguinii)
This is a medium-to-small forest tree from central and southern China. It bears small nuts, three to a burr. Seguin chestnuts often have the odd habit of continuously flowering all summer until fall. They are extremely precocious, sometimes bearing nuts by age two. They have been used primarily in wildlife plantings. I believe they hold great potential for breeding extremely high-yielding trees. They are hardy to zone 5 in some populations.
Henry Chestnut (Castanea henryi)
This tree is native to southwestern China, where it grows to heights of around 80 feet. It bears a single small nut to a burr. It has not been used in the US, because it’s not that cold-hardy. An interesting species, nonetheless. I would love to walk in a forest of Henry chestnuts. They often grow in mixed forests of Seguin and Chinese chestnuts.
Castanopsis Genus
This genus is very closely related to chestnuts and includes 120 species. Almost all members of the genus are native to tropical and subtropical regions of Southeast Asia from Borneo to Japan. There is one species native to California, C. chrysophylla, known as the golden chinkapin, that grows among the redwoods. Castanopsis trees are large timber trees growing in a wide range of soils, from bog to ridgeline. They make edible nuts very similar to small chestnuts.
Around the world chestnuts grow in many different conditions and in several forms. They can be found in both acid and alkaline soils, cold and hot regions, and humid and dry areas. Chestnuts can be massive forest trees, small spreading orchard trees, or tough thicket-forming shrubs. There is a chestnut tree well adapted to almost every bioregion in the world.
The Epic Saga of the American Chestnut
The American chestnut may well be the greatest and most useful forest tree to ever grow on this Earth. Its decline is considered by many ecologists to be one of the greatest ecological disasters to strike the US since European contact.
It is hard for us today to understand what was lost because we did not witness it. Imagine working in your yard and noticing an apple tree with wilted leaves. A few weeks later, the tree dies. You’re sad about this and tell a friend, who tells you that they had the same thing happen. Then you hear it from lots of people. It’s on the news. Apple trees are dying, orchards are wiped out, wild trees disappear. No one knows what to do. Before you know it there are no cider barns, no crisp fruits to sink your teeth into, no apple blossoms in the spring, no fruit in the supermarket. How would you feel? As the years go on, you might try to explain to young people what an apple tasted like, what it felt like to bite into apples; you might describe the trees’ gnarly growth habits or the smell of cider in the barn or the taste of applesauce. They would never understand. The apple tree would be gone and life would go on. Other trees would be there, but none would be the apple. This is basically what happened to the American chestnut. The chestnut was no less loved or used than apples are today. It was a tree with full cultural, economic, and wild significance. We are the people who were born after its loss. All we have are the stories and a handful of pictures to go by.
American chestnuts growing in the Appalachian Mountains. Photo courtesy of Forest History Society Durham, North Carolina.
Castanea dentata dominated the eastern US, making up roughly one-fourth of the trees in its range. This is a huge percentage, considering the diversity found in the eastern deciduous forests. Even maples, oaks, and ash are not that common.
American chestnut trunks were massive, often 10 feet or more in diameter, with canopies reaching 130 feet in the air. These arrow-straight, towering trunks were made of high-quality, rot-resistant timber. The wood was used for barn beams, house framing, furniture, telegraph poles, fence posts, paper pulp, caskets, and cradles. There is no wood so versatile as American chestnut. It has the durability of black locust, the straight grain and splittability of ash; it’s as stable and easy to work as pine, and very fast growing.
The wood value alone would have made the American chestnut a highly valuable tree. Adding the dependable crops of nuts makes this tree stand alone in its excellence. The wildlife value of American chestnut was unparalleled, as nuts could fill the forest floor more than a foot deep in some years. Along with wildlife, people also ate wild American chestnuts. They grazed their animals under these magnanimous giants during the fall and gathered nuts by hand. Chestnuts were collected in great quantities throughout the Appalachian Mountains, and roasted and sold on the streets of towns like Boston, Philadelphia, and New York. Train-car loads were filled with this wild crop. Today many families find financial relief with their end-of-year tax credit. Back then people found their Christmas bonus in the form of selling what chestnuts they could gather in the mountains.
The American chestnut was a keystone species in the ecology of the Appalachians. It was culturally fixed in the minds of Americans, and used widely. Tanneries cranked out leather that was processed with the tannins of chestnut bark, paper mills pulped the wood, railroad companies laid track with timbers, people built barns and houses, fences, and chairs. They ate the nuts raw and roasted every fall. And then it all crashed.
In 1904 chestnut blight, Cryphonectria parasitica, was discovered in the Brooklyn Botanic Gardens. From there it spread like a wildfire, consuming trees and turning forests of green into silvery gray ghost woods. Within just 25 years an estimated four billion trees died. An entire ecology, an entire culture, was wiped out. While the trees were dying, the US Forest Service advised people to have all their chestnuts logged. Believing there was no hope, they told folks to get some lumber out of it while they still could. We will never know how many resistant trees were killed in this shortsighted practice. Sadly, this mind-set persists today, as foresters commonly advise landowners to log all their ash and hemlock trees before the coming crash.
The Shelton family in Tennessee pose in front of a blight-killed American chestnut (1920). Photo courtesy of the Great Smoky Mountains National Park Library.
Cryphonectria parasitica is a fungus whose spores spread by wind. Its origins lie in Asia, where trees there have co-evolved with the fungus. When Japanese chestnut seedlings were brought over to the US for people’s gardens, no one noticed that these seemingly healthy trees carried the blight with them. The American chestnut had never encountered this fungus and so had almost zero resistance. People scrambled to save the chestnut tree in vain, employing all sorts of strange strategies over the next several decades before giving up for the most part.
There were some really wonderful early attempts at saving the American chestnut, notably the work of Arthur Graves. He planted several thousand seeds of anything he could get his hands on, including every species of chestnut from around the world. He crossed every species and then crossed the resulting hybrids. Many of his trees are still alive and maintained to this day at the Connecticut Agricultural Experiment Station by the committed and innovative work of Dr. Sandra Anagnostakis. Graves was never able to find the winning combination of a true timber-type tree and full blight resistance—though he found many trees that came close. The work of Graves and Anagnostakis continues today. Dr. Anagnostakis continues to plant trees, make controlled crosses, and spread hypovirulence. Today the Connecticut Agricultural Station and Sleeping Giant State Park are home to the largest repository of chestnut genetics in the world.
The forest left behind by Arthur Graves at Sleeping Giant State Park, in Connecticut. All the trees in this photo are mixed species of chestnut.
Other attempts at saving the American chestnut included cutting out all the trees in a large swath of land across Pennsylvania to act as a kind of firebreak. The budget for this project was enormous but could not keep up with the winds that carried blight spores. In the 1950s, when nuclear power was at the height of popularity, people irradiated nuts to hopefully invoke a mutation. Of course, this failed miserably.
The breeding program at the Lockwood, Connecticut, Agricultural Experiment Station run by Dr. Sandra Anagnostakis. This program includes species from all over the world and extends through many different plantings. This particular planting is a mix of American chestnut and Ozark chinquapin and also includes genetics of Japanese and Henry chestnut.
As the years wore on, and generations passed, interest in the chestnut grew less and less. The American chestnut became a legend, with little practical hope of recovery. That is, until two visionary men in the 1970s, Dr. Charles Burnham and Phil Rutter, came up with a plan. It was simple enough: Cross American trees with resistant Chinese trees. The resultant seedlings would then be backcrossed with American trees again and again until they had a tree that would behave like the American chestnut of ancient forests. The tree they worked to create would have fifteen-sixteenths American genetics. This would take several generations of crosses. Dr. Burnham knew he would never live to see the full breeding program to its completion, but he started it nevertheless as a selfless act. This was the beginning of The American Chestnut Foundation (TACF).
TACF would go on to plant thousands and thousands of seeds from multiple lines of genetics. For every tree they leave to grow, hundreds are cut down in this rigorous and highly organized breeding program. Today TACF has trees that are fifteen-sixteenths American and display both timber form and blight resistance. These trees are being planted experimentally in parks, at private homes, at institutions, and in reforestation efforts.
Chestnuts at Hemlock Grove Farm, West Danby, New York. These trees were planted by Brian Caldwell, who has been planting and selecting productive, blight-resistant trees for the past 40-plus years. Several of Brian’s trees originate from the plantings at Sleeping Giant State Park.
Many folks, including myself, continue to plant and grow 100 percent pure American trees as well as hybrids. American chestnut seed is available through TACF state chapters. The trees grow quickly. They typically live for 15 years before succumbing to blight. In this time they produce small crops of nuts and excellent pole wood. Since the blight cannot kill the root system, the trees sprout back after the blight knocks them down. They can be kept going indefinitely in a coppice system. Growing American chestnuts from seed also expands the genetics of this magnificent species.
There are other programs in action today. The American Chestnut Cooperators’ Foundation grows only 100 percent pure American chestnuts. They maintain trees that exhibit resistance through grafting and seed collection.
SUNY’s College of Environmental Science and Forestry, along with the New York chapter of TACF, is genetically engineering blight-resistant chestnuts. They have introduced a wheat gene to resist the fungus. The trees are currently not released for public planting pending government approval. This program is considered by some native-plant enthusiasts to be superior to the traditional breeding program of TACF because the trees are less “contaminated” with Chinese genetics. However, it’s interesting to note that Chinese chestnut and American chestnut share most of each other’s genes; the hybrids that TACF grows are actually over 99 percent genetically American chestnut.
The story of the American chestnut is far from over. Today we can grow resistant hybrids or pure American trees. We can bring this species back into our parks, homes, and wildlands. There really is no reason not to. Millions and millions of people live in the range of the American chestnut. If just 1 percent of them chose to plant a few trees, we’d have a lot of chestnut trees around.3
Wildlife Value
What chestnut trees provide to wild animals is truly unparalleled. The only tree that comes even close is the oak, but oaks are very different in their fruiting habits, with a profound impact. There are many species of oak found around the world, very few of which bear regular annual crops. Here in the northeastern United States, oaks flower in early May. At this time we have highly fluctuating temperatures, and it is not uncommon for a freeze to wipe out nearly all the oak flowers. If no frost destroys the acorn crop and the oaks fruit heavily, they will often take the next year off and produce only a very light crop, even in the absence of late frosts. Generally, oaks produce a heavy crop every two or three years. In fact, almost all trees produce heavy seed crops on an irregular basis. The chestnut stands alone in reliability. It is the manna tree.
Chestnuts flower very late here, around the end of June or early July. Their blossoms almost never encounter frost. They bear fairly consistent crops every single year. This is a highly valuable and unique trait among fruit and nut trees.
Chestnuts and acorns are heavy in starch. They are staples not just in the diets of humans, but also in the diets of many species of wild animals. They are the equivalent of rice or potatoes falling out of the sky. If you are a chipmunk or a squirrel who depends on this, then missing a crop every other year is totally devastating. This is why many rodent species (and their predators) in forests of oak, hickory, and beech will have boom and bust cycles in their populations. The addition of chestnut trees to a forest can significantly temper fluctuations in populations.
The list of wild critters that eat chestnuts is indeed a long one. It includes bears, wild turkeys, deer, raccoons, jays, opossums, skunks, foxes, squirrels, chipmunks, and several other rodent species. While it is easy to look unfavorably upon rodents, they are the backbone of the diet of several predator species that we revere, such as owls, hawks, and bobcats.
Chestnut leaves are eaten by over 100 species of Lepidoptera (butterflies and moths). Their flowers are a significant source of nectar for pollinators. Bark, buds, leaves, and twigs are fed on by a plethora of mammals.
It is hard to overestimate just how important chestnut trees can be for wildlife. They create a reliable staple food source that is nutritious, thin-shelled, and easy to consume.
Chestnut trees have a truly magnetic effect upon wild animals. They are centers of activity. Animals, birds, and people will travel from all directions to a stand of chestnuts. I can think of few greater legacies to leave behind than a stand of chestnut trees.
Wood
The timber value alone makes chestnut trees worth growing. Plantations of pine, spruce, and poplar offer people fast-growing timber resources. Chestnuts are another viable option for this, with many added benefits. It is a beautiful straight-grained hardwood that has found its way into high-value items like furniture, trim, and timbers.
Chestnut trees can grow very fast. They are easily coppiced. This means that they can be cut again and again because they will sprout vigorously from the stump. Coppicing chestnut is an old tradition in the U.K., where trees are put on rotation cycles ranging from 1 to 50 years depending on the desired wood products.
Chestnut wood is highly valued for many reasons. Not only is it a beautiful wood, but it is also light and strong. Chestnut is very stable and resists warping and cracking. It is easy to work and highly rot-resistant (rot resistance varies among species, with C. dentata and C. ozarkensis having the highest levels). Chestnut wood is a viable alternative to pressure-treated lumber; it is certainly more durable in contact with the soil. The rot resistance of American chestnut is on par with black locust. The main difference between black locust and chestnut is the weight and ease of use. Black locust is the gold standard in durability, but it is really hard to work with. Making things from locust often means broken drill bits, bent screws, and nails that will never be extracted by anything but fire. Chestnut is an easy-to-use, fine-grained wood that also makes durable fence posts. What other wood is this versatile? It splits easily, carves wonderfully, finishes smooth as glass, and lasts a lifetime if left out in the mud.
My friend Steve Serik of Hawk Meadow Farm inoculates shiitake logs for commercial production. He says chestnut logs grow the most and best shiitakes.
The wood also has such a mystique that I believe a person could make a living selling chestnut walking sticks or key chains.
Hybrid chestnuts gathered at Hemlock Grove Farm, West Danby, New York.
The Nuts
Chestnuts can be eaten so many different ways. The most famous way is roasted, but they can also be steamed or boiled, added to soups, made into candies and creams, or ground into flour and used in breads, cakes, cookies, and even noodles.
Thinking of the chestnut as a nut will limit its potential as a food. Chestnuts are more of a grain than a nut. They have almost zero fat. Nutritionally they closely resemble brown rice. If you think of them as you do walnuts or pecans, you will only see them as a snack, just another tasty nut. But chestnuts are much more.
Eating Chestnuts
Because of their high starch content, chestnuts have been a staple in the diets of people wherever they have grown.
They can be eaten and prepared so many different ways that I can only hope to illuminate a few of them here. The possibilities for chestnuts as a food are endless. In the kitchen chestnuts are as versatile as corn or flour.
Harvesting
Harvesting chestnuts is one of my absolute favorite activities. Because the nuts are so beautiful, it’s as if I can’t help myself from picking them up. There is a deep urge to reach into a prickly burr and uncover the chestnuts inside.
When trees are not too big, I shake the branches to encourage as many nuts to fall as possible. This allows for prompt harvesting, which reduces the likelihood of animals and birds taking them and of weevils developing.
Some nuts will fall free of the burr and others will remain in it. Step on the burr and they should pop out. You can pick them up with your hands or a “nut wizard.” This hand tool has a wire basket on the end of a handle and picks up any nuts it rolls over. It’s pretty amazing that you can eliminate the need to bend over by using this simple tool.
There are also commercial mechanical chestnut harvesters. They operate similarly to machines that pick up golf balls. The truth is that hand harvesting is great fun, and it’s not hard to find help. People will come from all directions to help harvest chestnuts if you put the word out. My friend visited a farm in Ohio that harvests 65,000 pounds of chestnuts a year—all by hand. It’s just the farmer and two Amish families.
Curing
When chestnuts first fall from the tree, they can be quite bland, and they need to be cured to sweeten up. If you store them in plastic bags in the fridge, curing takes a couple of weeks. As time goes on the nuts will get sweeter and sweeter—until late winter, when they start to sprout. If stored at room temperature, chestnuts will cure within a few days. There is no harm in eating chestnuts right off the tree, but their true flavor will not come out until after being cured.
Storing
Keeping chestnuts from drying out is essential if they are to be roasted. They can be stored in plastic bags in the fridge. Check to make sure that excessive moisture does not build up in the bag, and vent the bag if necessary. They can get moldy in the fridge if it’s not cold enough. The ideal temperature for storing chestnuts is 32 to 34°F (0–1°C).
Fresh chestnuts can also be packed in moist sawdust or sand in a root cellar at a warmer temperature. I have stored them for months at 40 to 50°F (4–10°C) by packing them into bins of sand. They keep well until spring when they sprout.
If chestnuts are to be dried or ground into flour, they can be hung in onion sacks and stored at room temperature for a long time. Dried chestnut kernels will keep well in a sealed jar for years.
Roasting and Boiling
Roasted chestnuts are a great treat during fall and winter. There is no good reason why American city streets are not full of vendors pushing carts of hot roasted chestnuts. My family particularly enjoys eating roasted chestnuts in the woods, cooked on a bed of hot coals. At home we set them on top of the woodstove for about five minutes on each side. It is okay if the shells burn a little; the nut is usually fine inside. I prefer the shells to burn a little and get the kernels to be slightly overcooked. They taste really good when they are roasted to the point of being fully golden.
Recommended cooking times and temperatures vary, but there is no wrong way to roast a chestnut. Cook it less and it will be crunchier; longer and it’ll be softer.
The shell needs to be sliced into, otherwise the nut can sometimes explode as steam inside tries to escape. Slicing the shell also makes peeling a lot easier. Many people slice an X-shape into the shell, but all that is necessary is one slice across the middle. Try not to cut through the whole nut, just the shell. A very sharp knife helps, and a chestnut knife is very safe and useful. This knife is curved like a hook and is specifically made for cutting rounded nuts. Chestnut knives are inexpensive and readily available online.
You can also boil chestnuts. Make a slice across the shell, the same as you would for roasting. Boiled chestnuts are delicious and peel very easily.
Roasting chestnuts.
Drying and Shelling
Drying chestnuts allows them to be used in so many different ways, from soup thickeners, to stuffing, to flour. I have found that the easiest way to dry chestnuts is in the shell, by hanging them in onion sacks over the woodstove or laying them out on screens. It can take a few weeks of hanging for the nuts to be totally dried, at which point the shells will be very brittle. You will know they are dry when the nuts rattle in their shells when shaken. If you put them in a dehydrator, be very careful to keep the temperature as low as possible. Over 100°F (38°C) and they are likely to slightly cook and change color. Their flavor will be off if that happens.
Once the in-shell nuts are dry, I run them through a Davebilt nutcracker. This is a small hand-powered device made for shelling hazelnuts and pecans, but it works well on dried chestnuts and acorns. A motor can be attached to the Davebilt. I attached a long handle to mine for increased leverage, and it is much easier to use than the short handle it comes with. You can also crack open the shells by simply crushing the dried nuts with a wooden stomper. If you place the dried nuts in a sack or pillowcase and then stomp, it really helps keep them in one place. Either way you will have to separate out the shells and pellicles (the skin between the nut and the shell) by winnowing or by picking out the nutmeats by hand. My friend John Walsh built an aspirator that runs with a shop vacuum. It’s a simple setup that separates nuts and shells very well with minimal effort.
Dried chestnuts were run through an ordinary corn grinder. The flour was then sifted to separate the coarse meal (top bowl) from the fine flour (bottom bowl).
An alternative method is to peel them while they are fresh and then dry the nutmeats. To do this, cut the chestnuts completely in half and steam them for about one minute. While they are still hot, they will pop right out of the shell if you squeeze them with a pair of pliers or with your fingers. This method removes the pellicle easily and well. It only works while the nuts are still hot. Do small batches at a time to keep them hot. The peeled chestnuts can then be dried for later grinding, or they can be ground up while still wet in a food processor. You can use this wet flour right away in baking or dry it for future use. You can also use these peeled nuts whole in a variety of dishes like stews and stuffings.
Personally, I like to keep a jar of dried, peeled kernels in the cupboard. Pour some in a pot to boil for 20 to 30 minutes and you have an easy, delicious snack.
Flour and Meal
Making flour from chestnuts is the epitome of tree crops to me. Here is the actual grain falling from trees, the manna from the sky. This is not a new idea. Traveling to cultures outside the United States, we can find endless recipes calling for chestnut flour, especially in Italy and France. It is a very tasty, sweet flour that makes excellent desserts, but is also great for thickening stews, adding to stuffing, or just as a stand-alone bread. Chestnut flour is gluten-free. Breads baked with 100 percent chestnut flour resemble corn bread in texture. Cakes made with chestnut flour are dense and remind me of pound cake. It is a very high-quality flour with endless uses.
Chestnut flour even has an excellent shelf life. I have kept bags of it in the cupboard for up to two years without a hint of rancidity.
You can grind up chestnuts in an ordinary cornmeal grinder or a flour mill. To get them to fit into a flour mill, you will have to make the nuts smaller. I pre-grind them in a corn grinder. Some folks beat the dried kernels in a sack with a hammer. The dried kernels will shatter. If you only run them through a corn grinder, you will have a very coarse meal. If the resulting meal is then sifted, you will have a pile of fine flour and one of coarse meal. The coarse meal is an excellent soup thickener, is great in cookies, or can be boiled just like grits or oatmeal.
The fine flour is an excellent ingredient for so many baked goods. It does wonders for the consistency of cakes particularly. Chestnut flour is also great in all pastries, biscuits, and breads. It will not rise like wheat, so in many recipes chestnut flour replaces 50 percent of the wheat flour. However, I really prefer breads and desserts that are 100 percent chestnut flour. Chestnut flour is sweet and delicious by itself. There are endless chestnut flour recipes on the internet and in Italian and French cookbooks. The Chestnut Cook Book by Annie Bhagwandin is a great resource.
I am not a chef or a baker. I think every serious chestnut grower should be partnering with people who prepare food. Surely an entire culinary school could be devoted to working with chestnuts.
Candied Nuts
There are several forms of candied chestnuts available today. The most famous are marrons glacés. Premium, specific nuts are selected for this process in which kernels are slow-cooked in sugar water until they fully absorb it and turn into the most beautiful-looking candy you’ve ever seen. Making marrons glacés is an art and a science. We’ve tried making them at home, but they’ve never come out as good as the pros’ versions.
Chestnut cream is a product in which candied chestnuts are pureed into a cream. It’s fantastic spread on toast and has the consistency of thick butter.
Livestock and Wildlife
Another way to eat chestnuts is to eat the animals that eat them. Roughly 90 percent of our corn- and soy fields exist to feed livestock. This can be reduced in two ways. The first is by planting chestnut trees in and around pastures. The animals can harvest the mast with no work or processing on our part. Livestock can also be rotated through chestnut orchards after harvest to clean up any leftovers, thereby diminishing pest populations.
The second way to feed chestnuts to livestock is to harvest and dry the nuts. To make this commercially viable, mechanical harvesters and dryers are needed. This equipment already exists; it is just the orchards and hedges that need to be planted.
Commercial chestnut varieties are easy for pigs, sheep, and cows to eat, but they are too big for poultry. Allegheny chinquapins are much smaller and can be harvested by large poultry breeds without any processing.
For farmers looking to supplement grain feed, chestnuts offer a viable option. There is a long history of people feeding chestnuts to cattle, hogs, and sheep in Europe and the United States. Often animals were simply allowed to graze under trees, but nuts can also be harvested and dried for future feed. For larger animals, they don’t even need to be shelled. For poultry, they can be ground up with shells included. The processing is quite minimal.
Chestnut trees attract and feed a lot of wildlife, including highly valued game animals like turkeys and deer. Every year hunters grow food plots of alfalfa, clover, and turnips to attract deer, but a few established chestnut trees would accomplish the same goal without the need for replanting. Chestnuts can be turned into meat, just like corn, alfalfa, and soy. They are a staple crop in every sense of the word.
Comparing Chestnuts and Corn
Think of the ecology of a cornfield, especially a field of Roundup-ready corn that has virtually no weeds in it. There’s really not a lot going on; not many places for hawks, butterflies, or honeybees. A chestnut orchard, on the other hand, is buzzing with life. There are 125 known species of Lepidoptera that feed on chestnut leaves.4 The trees provide roosting and nesting sites for birds. In contrast with corn, they have extremely low fertility requirements. Chestnut trees can grow on steep hillsides where bare rock is exposed. They can heal and build soil instead of using it up.
I think it’s pretty obvious to most people that the ecological diversity of a planting of chestnut trees is far beyond that of a field of corn. Of course, the big question people ask is, “Can an acre of chestnut yield as much as an acre of corn?”
It seems like a straightforward question that should have a straightforward answer, but it does not. An acre of fertile farmland is not equal to an acre of rocky hillside. There is also quite a bit of history to catch up on.
In 1929 when J. Russell Smith published his revolutionary work Tree Crops, corn and chestnut had similar yields per acre. He compared the yields of corn and wheat throughout the East Coast and Midwest with yields of chestnuts in Italy, France, and Corsica. Pound for pound, they were about the same. In some cases chestnuts were more and in some they were less, but overall there weren’t any big differences. This was back in 1929, when corn and chestnuts averaged a little over 1,000 pounds per acre.5
Since then corn has been intensively bred to boost yields, with the full support of government agencies and universities. It is grown today with a full array of chemical herbicides and fertilizers. Its yields have become monstrous, to the detriment of the land it grows upon. This amount of breeding work and intensive farming has not happened to the chestnut. Despite the lack of breeding, chestnuts may still outyield corn today. A high-yielding cornfield now produces over 7,000 pounds per acre, while a high-yielding chestnut orchard yields 2,000 to 3,000 pounds per acre. So how can I say that chestnuts can still outproduce corn?
Corn requires fertile, well-drained bottomlands. It is grown in the richest fertile valleys that were formerly prairie. It is heavily grown in the Midwest upon some of the best farmland on the planet. Modern corn growing needs this; it needs flat places for large machines. It needs soils that can be cultivated again and again. Chestnuts, on the other hand, can grow anywhere. They can grow on the poorest of soils. Dry ridgelines, steep mountainsides, land that few people would deem worthy of farming is where the chestnut can thrive and produce heavy crops year after year with zero inputs. I would like to see a cornfield that thrived on a hillside without any weed control or fertilizer.
There are other layers to the productivity of a chestnut orchard. An acre of chestnut trees can easily accommodate grazing animals, shrubs, herbaceous plants, and mushroom logs underneath the canopy. Multiple crops can be harvested in the same space. An acre of chestnut trees can exist on landscapes where it would be virtually impossible to cultivate corn. So where is the acre of comparison between corn and chestnut? Is it in the very best fertile bottomland, or is it up in the hills with livestock occupying the same space? In many cases, chestnuts will crush corn in yield per acre. In all cases, they will have tremendously more biomass and biodiversity.
Because chestnuts can easily be grown in conjunction with other crops in the same space, and they can do so in places that corn could never grow, chestnut and corn yields are incomparable. They are very different uses of land, and the total amount of food produced will vary considerably depending on if you count all the crops grown inside a chestnut planting.
The technique of grazing animals beneath nut trees is not a new one. Today it is known as silvopasture; in ancient Portugal it was known as the dehesa system. When done well, by rotating livestock through the orchards, it is a proven sustainable method that has worked for thousands of years.
Annual grains are just that, annual. They die every year and have to be replanted every year. Chestnuts can live for thousands of years. They can start producing as early as age two, and will increase their nut production each year.
Farmers looking to convert fields of corn to chestnuts can do so with a technique called alley cropping. Here you plant rows of trees right into the field and continue to grow annual crops in between the rows. As the trees get bigger, the alleys of annuals get smaller, until eventually they are totally eliminated. This method can allow you to continue generating income during the transition period.
If we want to improve wildlife habitat, grow crops with ever-increasing yields, protect and build soils, and reverse climate change, then planting chestnut trees is one way to accomplish all of these wonderful and attainable goals.
Chestnuts in bloom. They smell pretty weird, but they are beautiful and beneficial to many pollinators.
Cultivation
Cultivating chestnuts isn’t difficult if a few things are tended to. The trees do best with abundant sunlight, good drainage, and protection from voles and deer.
Pollination
Chestnuts are primarily wind-pollinated, monoecious trees (each tree produces male and female flowers). Though they are wind-pollinated, insects do play a large role in spreading pollen. They do not pollinate themselves, so two or more should be planted less than 50 feet apart. Occasional hybrid trees will have male-sterile pollen. This means they can receive female pollen and make nuts, but they can’t pollinate other trees. For this reason, I think it’s a good idea for people to plant at least three trees together.
Soil Preferences
Chestnut trees have a moderate-to-fast growth rate, similar to that of red maples. Of course, this depends on soil and tree health. They prefer good drainage and an acid pH, but this does not always have to be the case.
I have seen wild American chestnuts growing in low-lying swampy areas. At first glance, it seems that they can tolerate wet feet, but a closer look at the topography reveals something else. In older forests the ground is very uneven. As large trees topple over and are uprooted, a depression is created where the root mass once was. As the root ball breaks down, a mound is formed. This landscape feature is referred to as “pit and mound” or “pillows and cradles.” It is associated with almost all old-growth forests.
Pit-and-mound landscapes are essentially covered with vernal pools and raised beds (see “Uneven Ground” in chapter 2). Chestnuts, like almost all trees, prefer to grow on the mounds. If you have a wet field and want to grow chestnuts—or really any other fruit or nut tree—then make some mounds. Because without decent drainage around their root crown, chestnuts will languish.
Virtually all literature on chestnut cultivation speaks of the trees’ demands for acidic soil. However, I believe this depends on individual trees and species. I have on several occasions witnessed very healthy, mature chestnuts growing in alkaline soils. I believe that trees containing European and Japanese genetics are more likely to tolerate alkaline soil, but I have no scientific evidence to back this up. I also believe that high organic matter content in the soil will allow for greater flexibility of the tree to withstand differences in pH.
Spacing
Conventional wisdom is to plant trees on 40-foot centers. This is a big area for a small seedling to take up. Eventually, of course, the trees will be very large. In some old European orchards, only four trees fit per acre. There are several ways people have chosen to use the space that is not yet taken up by the young tree.
One method is to interplant chestnuts with shorter-lived species such as peaches, raspberries, and asparagus. By the time the chestnuts are spreading their shade, these other plants will be on the decline. With the same ideology, some farmers use alley cropping to grow vegetables, grain, or hay in between the rows until the chestnuts get big.
My favorite method for spacing chestnuts is to breed them along the way. I plant rows of chestnuts with trees set out only a few feet apart. As the trees mature, I thin out all but the best-producing trees. This may sound expensive, but it is far cheaper than purchasing grafted trees, especially if you propagate your own seedlings. I keep rows 40 feet apart with trees set 2 feet apart within the row. These numbers are my personal preference; some growers go with more space, some with less. I heard Phil Rutter (co-founder of The American Chestnut Foundation) talk in an interview about planting chestnuts in a double row 18 inches apart. He described walking down the rows of trees and finding exceptional producers that stand out. I have not planted nearly as many trees as Phil Rutter, but I have definitely found trees with exceptional qualities by overplanting.
Pests and Diseases
There are a few pests that can cause damage to chestnuts. A single grower is unlikely to encounter all of these. Chestnuts have far fewer pests to worry about than most fruit trees, but they are serious issues to pay attention to.
Chestnut Weevils
The chestnut weevil is the most difficult and notorious to deal with, especially for the organic grower. There are two species, Curculio sayi gyllenhal and C. caryatrepes boheman. Essentially they cause the same damage and have the same life cycle.
When burrs are forming in late summer, the adult chestnut weevil will fly up and lay eggs into the nuts. The eggs won’t do anything until the nuts fall from the tree. At this point they’ll turn into a larva and start chewing their way through the nut, eventually emerging anywhere from 3 days to 6 months after nut fall. They look like disgusting small white worms and ruin the nuts. After they exit the nut, the weevils burrow down into the soil, morph into adults, and emerge the next year to fly up and lay eggs. Infestation in unmanaged plantings can reach close to 100 percent.
Two methods of organic control of chestnut weevil exist today. The first is sanitation. This means keeping a chestnut planting clean and free of fallen nuts. The life cycle of the weevil is broken if they cannot emerge from the nut into the ground. Every nut has to be harvested for this to work, and there cannot be unmanaged trees nearby (within a mile). Livestock can help thoroughly harvest all the nuts, but they must be picked up before larvae exit.
If orchard sanitation is not an option because of wild trees nearby, or because squirrels are carrying nuts away and burying them somewhere else, then hot-water treatment can be used. This also involves prompt harvesting of the nuts. When the chestnuts first hit the ground, the eggs are very small and unnoticeable. If you put the nuts into a hot-water bath the same day, then the eggs will be killed before they mature into the larvae. In order for the nuts to not be cooked or killed in the bath, the temperature should not exceed 120°F (49°C), and they should not be left in for more than 20 to 30 minutes.
The New York Tree Crops Alliance that I am a part of is currently experimenting with other organic controls. Unfortunately, almost no university research has gone into this. During the upcoming season we’ll be spraying burrs during the month of August with a mix of clay, neem, and Grandevo. We will also be checking on the effects of spraying burrs with thyme oil. The weevil is a pest that must be kept in check for commercial production of chestnuts to succeed.
Ambrosia Beetles
Ambrosia beetles tunnel into the trunks of young trees and form galleries where they cultivate pathogenic fungi. Untreated, ambrosia beetles will kill a young tree within a week or two. However, you can save trees that have been invaded. If you see small white sticks of frass perpendicular to the trunk, ambrosia beetles are in there. Immediately spray the trunk with pyrethrum—an organic product derived from chrysanthemum flowers. It is a broad-spectrum insecticide. Fortunately it has a very short shelf life in sunlight, only a few hours. Spraying it directly onto the trunk where the beetle frass is will take care of them and minimize harm to other insects. You cannot dig out the tiny beetles. Spraying is the only thing I have found that works. Ambrosia beetles only attack trees during a very short window, when the leaves are first emerging but not yet full-sized. Once leaves are full-sized, the trees are safe for the year. So checking young trees every spring during this time can save them.
Ambrosia beetles are the scariest pest for seedlings. They kill very quickly and can affect dozens of other species besides chestnut. There is a good chance you do not have them in your local area, but if you do, they need to be controlled vigilantly if you are to establish young trees.
Asian Chestnut Gall Wasp
This wasp was accidentally introduced into the United States in 1974 on infested scionwood. The wasp lays eggs into the shoots of chestnut trees, and galls are formed. The larvae feeding inside the galls severely damage the new shoots of trees. Asian chestnut gall wasp is considered a major pest where it is prevalent, primarily in the Southeast. It can severely limit tree growth, and therefore nut production. Ozark chinquapin is the only species that carries any resistance.
Growers in areas without Asian chestnut gall wasp should avoid importing seedlings or cuttings from areas known to have it. This has been the primary way the wasp has spread.
Chestnut Blight
Cryphonectria parasitica has been totally devastating to American chestnuts and Ozark chinquapin, and very damaging to European chestnuts. Chestnut blight is a fungus spread by wind, insects, birds, and nursery stock. It is native to Asia, where trees have evolved to live with chestnut blight. For trees that are susceptible to blight, the fungus feeds on the cambium layer and girdles the tree. Interestingly, chestnut blight cannot kill the roots of a tree. There are too many competing fungi in the soil for chestnut blight to live. Some people have used this understanding to keep American chestnut trees alive by applying mud packs to blight cankers. This allows the tree to heal over the canker.
There has been a lot of work done involving viruses that attack the fungus. This hypovirulence has proven an effective control in some populations for several decades. The Connecticut Agricultural Experiment Station under the guidance of Sandra Anagnostakis cultures these viruses.
In my mind, the most practical and easiest method for dealing with blight is to plant resistant trees. There are endless sources for resistant hybrids and Asian chestnuts. There is a strong movement to find and breed resistant American trees. This is covered in greater detail in the section “Epic Saga of the American Chestnut.”
Blight resistance is a spectrum. No trees are immune to the fungus. Most “resistant” trees will have some branches here and there die of blight.
If you live anywhere in the eastern US, there is blight in your area. Few people realize how common wild American chestnuts are. Also, the fungus is able to remain dormant for decades, and the spores can travel hundreds of miles. There are parts of the Midwest and pretty much all of the western US that are blight-free, but this will likely not last forever. Sooner or later someone will bring some blight over on a tree or a piece of wood or something.
Ink Disease
Phytophthera cinammomi is just as terrible for chestnut trees as is the blight. Before the blight hit the United States, ink disease wiped out millions of trees in the coastal regions of the South. Ink disease has not been a problem in the North. Unlike chestnut blight, ink disease kills the entire tree, roots and all.
Ink disease thrives where soils become saturated for part of the year. There is no treatment. The best plan is to plant resistant trees in well-drained sites if ink disease is in your area.
All these pests and diseases may sound overwhelming, but it is most likely that a grower will only have to deal with one or two. It was 20 years before my friend Brian found chestnut weevils at Hemlock Grove Farm. I have never encountered Asian chestnut gall wasp or ink disease. Some folks don’t have to worry about blight or ambrosia beetles. Whatever obstacles your trees have to overcome, it will be worth it in the long run. Chestnuts can live for 1,000 years or more and are bothered by far fewer pests than most fruit and nut trees.
Propagation
Chestnuts are propagated either by seed or by grafting. While grafted chestnuts can have the benefit of bearing at a slightly younger age and bearing crops of large nuts, they have some serious disadvantages. The most important one is that they suffer from delayed graft failure. This occurs in about 50 percent of grafted trees. The top of the graft will die three to five years after it’s been made because of incompatibility issues. Some growers state that this won’t happen if the rootstocks are seedlings of the cultivar you are grafting. I don’t think that’s true, though.
Grafted chestnuts are also much more expensive than seedling trees. The main reason that I am not a fan of grafted chestnuts, however, is that they don’t further the genetic expansion of the genus. If there is one tree that really could use our help in this, it is the chestnut.
Seedling chestnuts will not be exactly like their parents, but they are similar enough that it’s not a big deal. Growing apples from seed is extremely variable, while with chestnuts you are going to wind up with a tasty nut just about every time. Sometimes the nuts will be smaller, but often they’re going to be similar.
To grow chestnuts from seed, it’s important to watch for three things: mold, early sprouting, and animals taking the nuts. Chestnuts need a cold stratification period, though some will sprout in the fall if left in warm conditions. To avoid early sprouting, I keep chestnuts cold. The fridge is barely cold enough. Outside is best (at least where I live). To keep rodents away from them, I place nuts in rodent-proof exclosures outside, in tote bins in the root cellar, or in buckets buried underground. In all cases I mix the nuts with damp sand (at about a 1:1 ratio of sand to nuts).
Sometimes they will sprout early. Be careful when handling sprouted chestnuts. If the radicles are long, you can trim them back. This will cause the root to branch out more. If the sprout breaks all the way off, they will make a new one, but this can weaken the tree.
If chestnuts get moldy, you can dip them in a mild bleach solution and repack them in fresh sand. Nuts that have been moldy but still sprout will grow rather bizarrely. They will often make a root that is no longer than half an inch and forms a swollen club shape. They are actually fine and healthy. If this happens, give them one more year and they will develop a large and normal root system.
Beds of chestnut seedlings at Twisted Tree Farm in early summer. By end of summer they will close the canopy. Once they go dormant in the fall, they will be dug up and ready for transplanting.
When chestnuts sprout above the ground, watch out for marauding critters who will pull the tree up to get the nut. In some cases you will need to protect from rodents as well as jays and crows. I often raise seedlings under bird netting, with mousetraps all around. The first few years I raised chestnuts in my nursery, nothing bothered them. Now word has gotten out and all the jays, crows, chipmunks, and mice recognize chestnut sprouts. They can dig up trees at any point during the first year and occasionally into the second.
Some people raise trees in pots close to the house to keep a close eye on them. This is fine for just a few trees. Beyond that, you would need a good system for keeping critters away. Bird netting, mousetraps, and a distance from squirrel habitat work well for me. Growing chestnuts in the ground as opposed to in pots makes a dramatic difference. First-year trees in a well-tended bed will grow anywhere from 1 to 4 feet with a nice root system covered in mycelium. In pots, trees will get around 12 inches tall with a less exciting root.
You can also direct-seed chestnuts into their final planting spot. This can work very well. Be sure to mark where they are planted. I use a 1-foot-tall tree tube to mark the planting and protect the nuts. Trees establish with the best root system possible with this method and require the least amount of water as their taproots can extend down very far the first season.
Commercial Possibilities
These are unlimited and very open right now. Around 95 percent of chestnuts consumed in the United States are imported. The demand for domestic nuts is nowhere near being met. I believe it is entirely reasonable that someone could make a living solely from growing chestnuts. Every grower I know sells all that they have. Thanksgiving and Christmas are peak times for fresh nuts. A cart of roasted chestnuts is almost guaranteed to do well in any urban center. I have heard of roasted chestnuts selling for as much as 50 cents a nut. Candied chestnuts, chestnut flour, cookies, and breads will appeal to a wide range of people including many Asians, Europeans, foodies, as well as gluten-free, paleo, and sustainably minded folks.
Chestnut orchards can be very productive, with yields ranging from 1,000 to 3,000 pounds per acre depending on site and cultivars. Wholesale, organic chestnuts can go for as much as $6 per pound; if you are selling retail, $10. And if you are processing them further, then the sky is the limit.
Chestnuts are one of the most dependable tree crops in the world. There is a chestnut industry taking off in Michigan, Missouri, Ohio, and soon New York. These states have been forming grower cooperatives that are helpful in getting nuts processed and marketed. Here in New York a group of us are just now forming the New York Tree Crops Alliance. I believe this is only the beginning; in the near future nut-growing cooperatives will cover the country.
When properly handled and prepared, chestnuts are delicious. Right now they are a high-priced specialty item, but that is only because more people are not yet growing and eating chestnuts in large quantities. We can actually accomplish amazing goals, like reversing climate change, improving wildlife habitat, protecting watersheds, and increasing biodiversity simply by eating more chestnuts. There is no good reason for our city streets, parks, yards, hedgerows, and farms to not be filled with chestnut trees. Every fall, kids and growers of all scales can be busy filling bins with the fruits of these generous trees.