Chestnut FAQ

 

Basic Basics

1. What are chestnuts?

Chestnuts are trees (and nuts) in the beech family, which also contains the oaks. They have been cultivated from antiquity in the Orient and Europe, with the result that Chinese, Japanese, and European chestnut nuts are much larger than wild nuts, but the Oriental trees tend to be small orchard trees, while the European trees are still large forest trees suitable for timber. The American chestnut tree was essentially wiped out by a fungus in the first half of the 20th century; it was also a big forest tree, with small sweet nuts.

2. Are horse chestnuts and buckeyes the same as "chestnuts"?

No; they belong to their own family of trees; basically horse chestnuts and buckeyes are as closely related to true chestnuts as bats are to giraffes. If you are familiar with European literature, there are endless opportunities for confusion; in England, "chestnut" means a horse chestnut; true chestnuts are called "sweet chestnut" or "Spanish chestnut". The confusion continues in other European languages, with multiple names for trees, nuts, wild vs. domestic, etc. Horse chestnuts and buckeyes are generally NOT edible; every year a few folks get hospitalized for trying to stuff a turkey with buckeyes- usually, the price is only a whopping bellyache, but more serious illness does happen.

3. What are they good for?

Chestnuts are an unusually useful tree, and possibly a very important crop in the near future. The wood is lighter than oak, but strong for its weight and attractive, works unusually well, with the only fault being a tendency to split easily (which is great if you're making shingles or rails, but not so hot for furniture). It's as rot resistant as redwood or cedar, and has fibers that are quite desirable for paper making. The bark and heartwood used to be the USA's single most important source of tannic acid. The forest trees grow very straight and fast (30% faster than oaks), and when cut down, they grow back from the crown of the existing root system very strongly (coppicing).  In the East, most of the first generation of telegraph poles were chestnut.

The nuts are unlike other nuts in that they are very low in oil (~ 2%), and spoil easily when fresh, but keep for years if dried properly. They have excellent protein, complementary to both beans and maize. Besides the fresh chestnut uses of roasting and going into stuffing, dried chestnuts can be ground for flour, and used in bread and pasta.  In Europe and Japan, candied chestnuts known as "marrons glaces" are a great delicacy, selling for $14/lb, or more. Both trees and nuts can also be used for animal feed. Importantly, even wild chestnut trees tend to have good nut crops every year, unlike oaks and walnuts.

4. What about the Chestnut Blight?

Chestnut Blight is a fungus native to the Orient, imported into North America about 1900, and from here to Europe a few years later- it kills 99.999% of pure American chestnut trees, and people still argue about how deadly it is to the European species; more of their trees survive, in any case. The few large American chestnut trees that survive are deformed, and their wood badly damaged by the disease. Europe still has a chestnut production industry, in spite of the blight; if you buy chestnuts in a regular grocery store, chances are 99/100 that the nuts are from Italy.

Chinese and other Oriental chestnuts are essentially resistant to or tolerant of the fungus; a few trees may die or be damaged, but most find the disease a minor annoyance. There is no hope the disease will "go away"- it also grows on oaks, oak bark, and even in the forest litter, since it is not a true parasite. The American Chestnut Foundation is working to move the disease resistance of the Oriental species into true American chestnuts, and their project is working-

5. Are OUR Chestnuts resistant to the Blight? - See The Root &Branch #4

6. Where will they grow?

Boy can you get into heated arguments on this one. Lots of people KNOW the answer. I don't, except to know that quite a lot of what people know is not true. A basic consideration in answering this question is what species you are dealing with; the different species are in fact just that; different species, emphasis on DIFFERENT. The fact that they can be crossed genetically does not mean they are similar in their environmental requirements.

Cold hardiness: Virtually all of the Chinese chestnut in this country is of sub-tropical or warm, wet, oceanic temperate origin, and will suffer from periodic cold damage anywhere north of Zone 5; if you can't grow peaches, don't try Chinese chestnut. Japanese; zone 6; European, zone 5; generally. American chestnut is more confusing, and it does depend on the origin of the seed; some Americans grow well into zone 4, even edging into 3, but not all; I've grown some pure American chestnut from NE Ohio, near Lake Erie, that was less cold hardy than common Chinese.

Soils: I've seen mature pure American chestnuts growing quite happily in pure sand, nearly pure clay, on mountain tops in granite gravel, and in black muck in a swamp 5 inches from skunk cabbage, with buttresses. In China, I've seen chestnuts grow well in wet tropical laterites, besides the more normal soils. Traditionally, people believe sandy soils are better, but I'm not sure this is anything more than looking at where wild trees are most often found; doesn't mean much in cultured situations. At Badgersett we have a deep loess soil (silt loam); pH about 6.5 usually, drifting down to 5.5. Wild chestnut forests are NOT found on limestone derived soils; but chestnuts will grow in limestone areas if provided with extra nitrogen in the fertilizer.

Rainfall: Historically, chestnut forests around the world are seldom found where rainfall is less than 40" per year, but irrigation can certainly serve in lieu of rain. At Badgersett, our average annual rainfall is about 28"; we do not irrigate, but have a deep soil with good subsurface moisture retention. In extreme drought years, we've had a few trees die, but only a few.

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Advanced Basics: Badgersett Hybrid Chestnuts

 

What is a hybrid chestnut? Hybrid chestnuts are NOT similar to hybrid corn. Without getting into too much detail, hybrid corn is all one species, from parental lines carefully bred to be complementary to each other, so the seed shows "hybrid vigor", ie, the seedling generation is more vigorous than either parent. Hybrid chestnuts are crosses BETWEEN SPECIES; of the first or later generations, and there is no guarantee or even expectation of "hybrid vigor". Species are crossed for a variety of reasons, usually to combine (hopefully) outstanding characteristics of each parent species in the offspring. Most commonly, Chinese chestnut has been crossed with American chestnut in the hope of finding seedlings that have the large nut size and blight resistance of the Chinese, and the greater cold hardiness, and possibly "timber-type" of the American. This sounds easy, and isn't.

What exactly are the Badgersett hybrids? Badgersett hybrid chestnuts are different from all other hybrids available elsewhere, in a number of ways. Our goal here has been to produce a DOMESTICATED chestnut tree, with good, multi-purpose, characteristics. We do NOT breed here to restore the wild American timber tree; that work is being done by The American Chestnut Foundation (which Philip Rutter was the founding President of, and spare me your comments about the preposition).

We use the crossing between species specifically to create genotypes impossible to find in the wild. For example: a tree which starts to produce nuts in the forest when it is 2 years old will die- because it has to compete with neighbors which are putting all their energy into growing up, into the forest canopy. Trees putting energy into nuts too soon will be shaded out, and killed. Our hybrids are intended to be closer to a Holstein cow, compared to pure species of chestnut, which might be more like a wild bison, in terms of milk production and tractability. Many of them will produce nuts in 3 years, and we continue to breed them for even earlier production. Experimentally, we have species hybrids which produce seed within 3 months- at the theoretical limit. (Some Seguin chestnuts will do this without crossing, but we have 2 such breeding lines with no Seguin in them.)

We started with hybrids from several amateur breeding projects (so we wouldn't have to start from scratch) and our lines are now combinations of Douglass, Gordon, Gellatly, Szego, Clapper, and Perry hybrids, besides crosses entirely our own. Our hybrids now contain American and Chinese species most frequently, with varying amounts of Japanese, European, and Seguin chestnut. At this point, it makes no sense to try to ascribe a species origin or even basic similarity to our plants; they are, in fact, domestic chestnut.

they are selected and bred for:

precocity - many will bear nuts in 3 years, some in 2, almost all by 5.

cold hardiness - our trees have withstood -39°F. Winters here are severe, Great Plains style- sunny, windy, and frigid; very hard on trees.

nut crop size- still increasing-

nut size, nut quality- our best are as good as any, anywhere-

tree vigor

tree health

What about the Chestnut Blight and Badgersett Hybrid Chestnuts?

We do not have the chestnut blight here at Badgersett, so we cannot test our trees here. However, years ago, comprehensive samples of our materials were sent to both China and Auburn University, in Alabama- blight is a fact of life in both places. Dr. Huang Hong-Wen conducted extensive observations on our chestnuts in both locations, and his results were published in Root & Branch #4; basically, he found about 80% of our seedlings to be functionally resistant to the blight, with about 20% succumbing to the disease. That is actually better than we had hoped, for hybrids of this sort. While it cannot be a guarantee of resistance, it is an excellent indication.

Are there any real problems with these hybrids?

Yes, there are; unlike the hazel hybrids, which are basically "restabilized" genetically after the cross between species, they hybrid chestnuts are NOT yet restabilized, and seedlings can be quite variable. The best are excellent, but some of the seedlings will be weak.

One particular problem in northern areas is a trunk infection from fungi not normally a problem to chestnuts. Apparently, the south side of the trunk can be injured in winter, when the sun shines on the trunk on a cold day- the surface of the trunk warms up considerably- and then the sun goes behind a cloud. The warm trunk quickly freezes, and injury results. Some of these hybrids appear to get infected this way, leaving the trunk weak. The problem decreases the further south they are planted, and we are working to increase the number of trees that do not have the problem- but right now, in our area, and north of here, the problem is real.

 

More to come...