How to grow, harvest, and eat chestnuts

Last Updated on October 24, 2023 by Aaron von Frank

Chestnuts are a fast-growing perennial tree that produce a delicious, sweet-tasting nut high in complex carbohydrates. In this article, you’ll find out how to grow, harvest, and eat chestnuts!

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Table of contents:

I. Chestnut introduction and the tragic history of American chestnuts
II. How to grow organic chestnuts
III. How to harvest chestnuts
IV. How to eat chestnuts + chestnut recipes
V. Chestnut FAQs

I. An introduction to chestnuts

Let us start out by acknowledging that the topic of chestnuts would be better covered in a thick book rather than a relatively short website article. That’s largely owing to the fact that chestnuts might well be the most important crop in human history, despite the fact that we Americans don’t hear much about them outside of a holiday jingle. 

As avid foragers and outdoor enthusiasts who enjoy everything from acorn flour to edible wild mushrooms, The Tyrant and I often wonder what the forests we explore today might have looked like a century ago. The answer: very, very different.

Chestnut forests 

We live in Upstate South Carolina surrounded by oak, poplar, hickory, and beech-dominated forests. However, if we could hop into a time machine and travel back to 1900, we’d find our familiar forests dominated by unfamiliar, gigantic trees: American chestnuts (Castanea dentata).

Throughout the Appalachian Mountain region that we call home, it’s estimated that 1 out of every 4 hardwood trees was an American chestnut, with an average mature height between 80-100 feet. By comparison, the tallest trees in our forests today are tulip poplars (sometimes called the “redwoods of the east”), with an average mature height of 70-90 feet.  

In early fall, the ground under these chestnut trees would have been covered in a thick layer of spiky burrs. Inside the burrs: large brown chestnuts, a deliciously sweet and nutty starch, long referred to as the “bread of the woods.” For millennia, human beings, their livestock, and all manner of wildlife relied on chestnuts as a critical food source.  

The greatest ecological disaster in American history?  

What’s the greatest ecological disaster in American history? Other than the Dust Bowl, you’d be hard-pressed to find a greater ecological disaster over the past few hundred years than the functional extinction of American chestnut trees. 

What caused American chestnuts to disappear?  

In 1904, Japanese chestnut (Castanea crenata) saplings were imported into New York City. Unbeknownst to anyone at the time, this event would have the same impact on America’s native chestnut populations as European-imported smallpox and measles had on Native American human populations. 

The imported Japanese chestnut trees were infected by a bark fungus (Cryphonectria parasitica). This fungus, aka “chestnut blight,” was native to Asia where it had co-evolved alongside native Asian chestnut species. Thus, Japanese chestnuts and Chinese chestnuts (Castanea mollissima) could survive despite being infected by the fungus.     

American chestnuts were not so fortunate, and had zero immunity to this foreign disease. Thus, chestnut blight rapidly spread to neighboring forests via spores, emanating out from the disease’s epicenter in New York City. Within a few decades, a staggering four billion American chestnut trees spanning 30 million acres of forest were dead. 

Today’s forests in the eastern United States are shadows of their former selves, but nobody alive today is old enough to remember what was lost. 

Breeding blight-resistant chestnuts today

Today, The American Chestnut Foundation, the US Forest Service, universities, orchardists, and plant breeders are working to breed and grow blight-resistant American chestnuts. Typically, this process involves breeding hybrid chestnut strains that have the blight-resistance of certain Asian chestnut species combined with the characteristics of American chestnuts.  

Meanwhile, The American Chestnut Cooperators Foundation is attempting to breed 100% true American chestnuts by cross-pollinating the small handful of surviving American chestnuts that exhibit a heightened degree of blight-resistance. This is a laborious and time-intensive task since it takes an American chestnut grown from seed about seven years to produce its first nuts and five years to start testing the tree for blight-resistance. 

If you have the means, please support these organizations so that American chestnuts or American hybrid chestnuts can once again be integrated back into our native forests! 

How to grow chestnuts in your home orchard, homestead, or food forest

Now that you have a bit of context about the history and importance of chestnuts, it’s high time you learn HOW to grow your own chestnuts! 

We’ve been growing chestnuts using organic methods for about eight years, and we’ll share everything we’ve learned (including our stupid chestnut growing mistakes).

What are chestnuts’ nutritional value?

One reason we originally decided to grow chestnuts is because we wanted a long-lived perennial plant that would produce starch/carbohydrates. Most nuts (pecans, almonds, walnuts, etc) feature a lot of good fats, combined with small amounts of protein and carbohydrate.  

However, chestnuts truly are the “bread of the woods.” Per ounce, chestnuts feature:

• 8 grams of complex carbohydrates
• ~0.5 grams of fat
• ~0.5 grams of protein
• high quantities of potassium, Vitamin C, and Vitamin B6, plus other vitamins and minerals.  

Many nights over the past month, The Tyrant and I have enjoyed cast iron-roasted chestnuts as the sole starch served at dinner. Our hope is to eventually produce enough chestnuts to fill up our freezer or even use as supplemental feed for our ducks.  

Want to put homegrown chestnuts on your dinner table? Here’s how: 

Step 1: Figure out spacing and location of your chestnut trees BEFORE you order them.

A. Check your agricultural zone.

Chestnuts can be grown from Ag Zones 5-9 (southern New England to North Florida). If you live in this range, you can grow chestnuts. 

B. Make sure you have enough space for at least two chestnut trees.

As mentioned previously, mature chestnut trees are massive. In 15-20 years, you may have a 60′ tall x 40′ wide tree, so plan accordingly…

This means do NOT plant three chestnut trees in your 10′ x 4′ raised bed. It also means you shouldn’t plant a chestnut tree right next to your house, unless you want cracks in your foundation and roof damage. 

You’ll also need to plan to have at least two chestnut trees planted within ~100 feet of each other (or less). This ensures that your chestnuts will be able to cross-pollinate in order to produce nuts. 

For reference, on our ~0.5 acre property, we have three chestnut trees. This way, if one tree dies, we’ll still have at least two trees left, and will therefore still be able to produce nuts. 

Even though chestnut trees are technically wind-pollinated, we see insect pollinators (mostly native bees) all over our chestnut flowers. We think they’re significantly assisting in the pollination of our trees, but have no way to prove that hypothesis. 

C. Check soil conditions. 

The ideal spot for a chestnut tree is in a sunny location with well-draining loamy soil with a pH between 5 – 6.5. Basically, the same exact conditions that oaks and hickories love.

Chestnut trees don’t like having wet feet, so don’t plant them at the bottom of a hill, in a boggy spot, next to a creek, etc.   

Step 2: Select and order your chestnut trees. 

We ordered Chinese chestnuts (C. mollissima) that feature:

• high blight resistance,
• large nut size,
• excellent nut flavor.  

However, other types of blight-resistant chestnuts are also available, including:

• Chinese-American chestnut hybrids (such as Dunstan chestnuts); 
• European chestnuts (C. sativa) cultivars or European x Asian hybrids; and
• Japanese chestnuts (C. crenata), although these have smaller nuts with lower quality nutmeat than their peers.  

You may even be able to find increasingly blight-resistant pure American chestnut varieties via your state’s chapter of The American Chestnut Foundation.  

Step 3: Plant your chestnut trees. 

When do you plant chestnut trees? 

The best time of year to plant chestnuts is somewhat dependent on where you live.

• If you live in colder northern climates, the ideal time to plant chestnut trees is late summer (August – September).   
• If you live in warmer southern climates, the ideal time to plant chestnut trees is in the fall (October – November). 

Overwintering chestnut saplings will have time to begin establishing their roots prior to bud and leaf formation the following spring, which will reduce transplant shock. You can also plant chestnut saplings in the late winter-early spring as soon as the ground thaws, but this requires the trees to establish roots while also leafing out. 

Five chestnut planting tips:

Now it’s time to transplant your chestnut saplings into the ideal planting locations you’ve selected (see Step 1 above for identifying ideal spots). Here are five chestnut planting tips to follow: 

i. Dig a hole about twice the size of the root ball or bare roots in order to loosen the soil to allow for root penetration.

ii. Do NOT add manure or fertilizer into the hole as this can burn the tree roots.

iii. If you have a high quality compost or worm castings, don’t add more than a 1:4 ratio to the native soil. Even better, simply fill the hole back in with 100% native soil and top dress the compost/castings on to the soil surface in a circle around the sapling, so the microbes and nutrients in the amendment slowly work into the soil. 

iv. Place 3-5″ of wood chips or untreated mulch over the soil surface (or over the compost/castings) around the sapling. This helps:

• reduce weed pressure,
• minimize drastic soil temperature fluctuations, 
• act as a slow release fertilizer,
• maintain more even soil moisture levels, and
• encourage a more fungal-dominated soil ecosystem similar to the forest environments in which chestnuts naturally grow (as opposed to a bacteria-dominated soil systems found in early stages of ecological succession). 

Warning: Do keep in mind that you do NOT want to pile compost, soil, or mulch above a sapling’s or mature tree’s root collar. (The root collar is where the trunk and the roots meet.) Doing so can invite infection and cause the tree to rot. So any top-dressed compost or wood chips should tier down to ground level as you approach the tree’s trunk.   

v. Deeply “water in” your transplanted chestnut tree with a hose immediately after transplanting. This ensures that there’s good soil-root contact with no air pockets.       

Step 4: Maintain your chestnut trees. 

a. Soil fertility 

We keep the ground around our chestnut trees covered in a thick layer of leaves or wood chips year round, for reasons detailed above. This helps provide ideal biological soil fertility for our chestnut trees, while also minimizing the likelihood of soil borne diseases/pathogens. Putting down a 2-3″ deep layer of compost prior to adding leaves or wood chips is ideal if you have access to high quality, affordable compost/worm castings.  

Another approach we’re experimenting with in addition to wood chips/compost is growing stinging nettles directly underneath our chestnut trees. Stinging nettles push right through the mulch in late winter, and provide a delicious winter-early spring crop for us before our chestnuts have started leafing out. The painful stings also keep pests like squirrels away from the tree. In late summer, we chop the stinging nettle back to the ground to allow for easy nut collection, and the nettle cuttings decompose, adding fertility back to the soil. 

A more conventional approach is to use fertilizers, which should be applied in the late winter or spring right before your chestnut trees are breaking dormancy. If you notice your chestnut trees looking weak or having yellowed leaves during the growing season, a well-balanced liquid fertilizer like kelp emulsion may be necessary.

Your chestnut tree will also appreciate an offering of free, homemade liquid gold (ha!).   

b. Irrigation

One thing we learned the hard way this year is to irrigate your chestnut tree if you don’t get good rain every week or so during the hot months. Over the past ~9 weeks, we’ve had about 0.25″ of rain and record heat, with 90+ degree temps extending into October. 

We didn’t irrigate our largest chestnut tree at all during this timespan. The result? The tree produced a nice yield of large chestnuts, but the development of many of the burrs has stalled, with small desiccated nuts inside. Due to water stress, we suspect that our tree put all of its energy/water stores into survival rather than reproduction.

We’ll probably have 50% less nuts than we could have if we’d had the sense to irrigate. Lesson learned! 

c. Pruning 

Chestnuts should be pruned with a central leader structure in mind. The ideal time to prune chestnuts is in the winter.

Rather than diving into the specifics of chestnut tree pruning here, we’d advise you to follow Michigan State University’s chestnut pruning guide. 

Also of note: save your pruned chestnut branches! We cut ours up into small pieces, dry them, then use them for smoking wood or as fuel in our wood-fired cob oven. 

d. Pests and disease management 

In our opinion, the best approach to pest and disease management is prevention, and the best prevention methods are integrated pest management (IPM) systems. Basically, using nature to control nature, whether that’s good fungi to control pathogenic fungi or predatory insects to control pest insects. 

This requires a focus on building healthy soils and developing polyculture plant systems so that no single pest or disease finds itself in the midst of an all-they-can-eat buffet of their favorite food with nothing around to slow or stop them.

As evidenced by chestnut blight, this approach isn’t 100% failsafe, and introduced pests and diseases can wreak havoc on otherwise healthy ecosystems. 

Nevertheless, we’d encourage home orchardists, forest gardeners, and homesteaders to use synthetic pesticides only as a last resort if all other prevention methods have failed. Even then, there are likely OMRI listed/organic pesticide options available that are less damaging to humans and wildlife. 

Given how much wildlife we see frequenting our chestnuts and the fact that we and our ducks walk under them daily, we have not and will not ever use synthetic pesticides on our chestnut trees. 

What about deer and other pests?     

Here’s a good, inexpensive, and ridiculously simple method to help keep deer out of your yard or garden beds.

You may also want to seriously consider getting grow tubes for your young chestnut saplings to prevent trunk/bark damage which could easily kill a young tree.

III. How to harvest your chestnuts

Now comes the best part of all: years of planning and work finally pay off. Time to harvest your chestnuts! 

How long does it take chestnuts to produce nuts?

Chestnuts started from seed may take seven years to produce nuts. While all species of chestnuts are genetically similar enough to cross-pollinate, you won’t know the characteristics of the next generation’s nuts for another seven years. (That’s why you’ll probably want to buy chestnut saplings rather than start from seed.)

Chestnut saplings you buy from a nursery are usually a few years old upon purchase and will produce their first nuts in 3-4 years. 

Keep in mind that your chestnut trees will likely outlive you. In fact, hundreds of years is middle-aged for a chestnut tree. The oldest chestnut tree in the world is the 4,000 year old Hundred-Horse Chestnut in Sicily, which has quite a story. 

How much nuts can a chestnut tree produce? 

The quantity of nuts that a chestnut tree produces can vary depending on:

• the species and cultivar;
• the health of the tree;
• the growing environment (more crowded trees will produce less);
• the age of the tree. 

Under ideal conditions, a single mature 15-20 year old chestnut tree can produce up to 100 pounds of nuts. Considering a single dinner serving of chestnuts might be about 6 ounces, that’s a LOT of food! 267 servings to be exact.

It’s easy to see how chestnut trees could be an incredibly valuable food source for you and your family, just as they’ve been for humans throughout human history.  

How do you harvest chestnuts? 

Assuming you’re not a commercial chestnut farmer with thousands of dollars in harvesting equipment at your disposal, you’re going to be harvesting your chestnuts the old-fashioned way: picking them off the ground by hand. 

This might jokingly be referred to as a “you-prick” operation, given how sharp and spiny chestnut burrs are. In our southern climate, our Chinese chestnuts start producing in September and wrap up by mid-October (about 6 weeks). Chestnut harvesting season is a bit later in northern states.  

Here are a few chestnut harvesting tips and tricks we’d recommend:

i. Harvest nuts every 1-2 days once the trees start producing. You’ll notice the burrs browning, splitting open, and dropping to the ground (both nuts and burrs) as your harvesting season starts. 

Regular harvesting will help prevent wildlife from finding the nuts. You can give younger trees a bit of a shake to bring more lose nuts down, but a mature chestnut tree will simply laugh at you for trying to shake it. 

ii. Wear very thick gloves. Chestnut burrs are no joke. 

For burrs with nuts still inside: hold the burr in your non-dominant hand while splitting open and removing the nuts with your dominant hand. 

iii. Use two buckets. One bucket is for nuts, the other is for burrs. If you leave the burrs on the ground, it becomes increasingly difficult to find nuts as the season progresses. 

Chestnut burrs are great for compost or for fire kindling. 

iv. Immediately rinse and dry your chestnuts after harvest, prior to storing. This ensures any dirt, unwanted debris, or insects are removed prior to storage.   

IV. How to eat chestnuts

Crack ’em open and eat ’em? Nope, not with chestnuts. 

While chestnuts might taste pretty good raw, you should cook them first. That’s because they have fairly high levels of tannic acid, which can lead to stomach aches and worse. However, when you cook chestnuts, you degrade those compounds making them safe for consumption, even in large quantities. 

You can eat cooked chestnuts whole, puree them into mash (similar to potatoes), or turn them into chestnut flour for various baked goods. (See: How to make chestnut flour)

Below are chestnut recipes you’ll love!

• Cast iron pan-roasted chestnuts on a stovetop
• Chestnut crabapple mash
• One-pot roasted chicken with chestnuts and crabapples (or Granny Smith apples)
• Chestnut flour cake with persimmons and buttermilk
• Chestnut spread infused with spruce needles
• Chestnut flour crepes with beautyberry whipped cream
• Chestnut breakfast porridge with pan-roasted Asian persimmons
• American persimmon pie with chestnut flour pie crust
• Chestnut and shiitake mushroom soup

V. Chestnut FAQs

Here are answers to some common questions we get about chestnuts: 

How big can chestnut nuts get? 

It depends on the species and cultivar. The largest chestnuts we’ve gotten from our Chinese chestnut trees are 20 grams. Apparently, there are Japanese chestnut nuts that can reach 40 grams. 

How do you store chestnuts? 

Note that chestnuts are prone to molding if not properly stored, so follow these storage instructions for best results: 

A. For chestnuts you plan to eat soon after harvest without storing:

As soon as your chestnuts are rinsed and dried, let them dry indoors out of the sun on a countertop (ideally on a drying rack to allow air circulation) for about 3 days. As the nut meat dries out and ages, the flavor sweetens and develops. 

After a few days drying time, they’re ideal for roasting or other recipes.  

B. For chestnuts you plan to store for weeks or months:

Rinse and dry your chestnuts for 12-24 hours. Put them into a freezer bag and store them in your fridge with the initial storage date written on the bag (so you know which ones to eat first). Put a folded paper towel inside the bag to help control humidity.

Under these conditions, your chestnuts can store for 2-3 months. Since they are living seeds intent on growing, they will eventually start sprouting towards the end of this time window. You can eat recently sprouted chestnuts, but the nuts’ flavor begins to deteriorate as they grow.   

Can you freeze chestnuts?

Yes, for long-term storage you can freeze chestnuts. We’ve never frozen ours, but some people report that frozen chestnuts don’t taste as good as chestnuts that have never been frozen.     

Can you dry chestnuts?

Yes. Many cultures dried chestnuts for long-term storage and/or to grind into chestnut flour. We have a detailed guide to make your own chestnut flour, a versatile ingredient for making baked goods, desserts, breakfast porridge, and more. 

What do chestnuts taste like? 

If you’ve made it this far, you probably read where we describe chestnuts as sweet and nutty, but what exactly do chestnuts taste like? If we had to identify the most proximate common flavor, we’d have to say that a plain roasted chestnut tastes most similar to a sweet potato. Not identical, but similar.  

Are all chestnuts edible? 

All true chestnuts (in the genus Castanea) are edible. The three most common cultivated chestnut species are:

1. Sweet chestnut, aka Spanish or European chestnut (C. sativa)
2. Chinese chestnut (C. mollissima)
3. Japanese chestnut (C. crenata)

There are other more obscure chestnut species (in the genus Castanea) that produce edible nuts as well. 

Are there any poisonous chestnut lookalikes?

The nuts of horse chestnuts (Aesculus hippocastanum) look similar to actual chestnuts. However, horse chestnuts are mildly poisonous. How to tell poisonous horse chestnuts apart from edible chestnuts?  

• Chestnut burrs are completely covered in spines, thus resembling a hedgehog curled up in defense mode. Horse chestnut shells (they’re not burrs) have a visible, smooth surface with scattered spines on the surface.  
• Horse chestnut nuts are rounder and don’t come to a point, whereas chestnuts have a point/tassel on the tip. 
• Eating something is a not a good way to ID it, but if you were to nibble a horse chestnut, the flavor would be very bitter. However, chestnuts have a sweet, starchy flavor. 

What’s the difference between water chestnuts and chestnuts?

Chinese water chestnuts (Eleocharis dulcis) and chestnuts (Castanea spp.) are unrelated plants. Differences:

• Water chestnuts do not produce nuts. The part of the plant that is eaten is the underground corm/storage root of the plant.
• Chestnuts are a large tree that grow on land. Chinese water chestnuts are a grass-like sedge that grows in aquatic environments.  

Another aquatic edible plant with the common name “water chestnut” is water caltrop (Trapa spp.). Trapa natans, aka European water chestnut, is considered an invasive species in the US. Water caltrop is not related to true chestnuts. 

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Now you have all the information you need to successfully grow and use chestnuts, one of the most important foods in human history! 

Be sure to follow our favorite chestnut recipes which we’ll expand each fall as we harvest more chestnuts and trial new recipes in our kitchen. 

KIGI,

Other nutty articles you’ll love:

• How to make roasted chestnuts on a stovetop | Web story video
• Recipe: Spruce needled-infused chestnut spread or chestnut mash
• Recipe: Chestnut flour crepes with beautyberry whipped cream
• Recipe: chestnut porridge, a simple & delicious sugar-free breakfast
• How to make chestnut flour
• One-pot roasted chicken with chestnuts and crabapples
• How to make acorn flour
• Recipe: Hickory nut ambrosia