biwa
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Location: Virginia, zone 7

American chestnut tree - Doomed to die an early death?

I just purchased and planted this tree in my backyard:

[url]https://www.tytyga.com/product/American+Chestnut+Tree[/url]

I have since been told that American chestnut trees die of a disease when their trunks reach 6 inches in diameter. Is there any way to prevent this?

MaineDesigner
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No, but they often re sprout from the roots. Six inch caliper is probably optimistic if there is a reservoir for the fungus in your area.

biwa
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Oh, it's a fungus, not a disease?

Fungus only grows on the surface of things, right? Maybe I could periodically burn the fungus away from the main trunk with a shortwave UV lamp (UVC light, 254 nm wavelength). Those are supposed to kill germs. Maybe it can kill fungus too.

MaineDesigner
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The fungus grows in the cambium layer. A UV light would have no effect although I suppose you could make an argument that it could impede fruiting if you timed it exactly right.

opabinia51
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Yes, Castanea are afflicted with an imported fungal disease from Europe which is really sad because they are native to North America and Aesculus hippocantineum (horsechestnut) which is poisnous and not native is the one that grows here.

However, if you spray your tree with an aerated compost tea and a diluted milk mixture you can help it a long. Of course, you would want to do more research into the epidemiology of the fungal disease to figure out some methods to help a tree along.

TheLorax
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MaineDesigner has correctly assessed the situation based on my limited experience with this disease. There are quite a few American elms left standing but sadly not so for our American chestnuts. Our landscape is loaded with those reservoirs mentioned by MaineDesigner for Chestnut blight therefore even if you have a resistant individual, the odds are very low it would survive to fruit and even if it did, I suspect it would succumb to the disease long before reaching maturity as resistance should not be confused with immunity.
Chestnut blight is caused by a fungus which entered our country on Asian nursery stock imported to New York around 1900. Spread by wind, rain, birds and other animals, it enters through cracks or wounds in the bark, multiplies rapidly, making sunken cankers which expand and girdle the stem, killing everything above the canker, usually in one growing season. Because it had never before been exposed to this fungus, the American chestnut was highly susceptible; like the native American tribes exposed to smallpox, the American chestnut was devastated throughout the natural range, extending over the Appalachian hills and highlands from Maine to Georgia. By 1940, three and a half billion American chestnuts had perished.
Three and a half billion American chestnuts is not chunk change to the species that depended upon them for survival.

There is however some hope out there-
https://oikostreecrops.com/store/product.asp?cookiecheck=yes&P_ID=122&PT_ID=73&strPageHistory=cat

This particular variety is loaded with American Chestnut DNA and I believe it to be well capable of helping fill the niche vacated as a direct result of the loss of our indigenous chestnuts.

Please, try one. I would encourage you and anyone else in a position to add a few to their landscape to do so. I have. I couldn't be more thrilled with the saplings I purchased from OIKOS. It is my intent to purchase a few more.

biwa
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Location: Virginia, zone 7

Lorax -

The Timburr Chestnut is the one you're recommending? I couldn't get the direct link to work so I browsed the chestnut section until I found one with a similar looking address.

Is there a way to tell what species went into making that hybrid? Is it half American and half Chinese or is it something more complicated than that? They've got the Latin name written there but I'm not sure if there's a way to tell what it is from that.

Thanks for your help.

TheLorax
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Timburr is the one I recommend because it has the most Castanea dentata (American Chestnut) dna. Call him on the phone and fire away with any question you've got. I had to call him to get some technical information several years ago and he was beyond informative.

Excerpt from their website on Timburr-
Timburr Chestnut — Castanea x dentata hybrid ECOS

Timber Growth Habit Like the American Chestnut
The most American-like hybrid cross producing vigorous seedlings with a dominant central leader. Much more American-like with high heritability. Created by using Douglas 2nd and 3rd generation trees along with other hybrid trees that show good form with little or no blight. The seedlings we grow are from the best seven trees that were selected over 20 years ago. Vigorous growth and upright habit were the priority. It took this group 4-7 years longer to come into bearing compared to our Chinese chestnuts. One tree is over 45 ft. tall and averages 2-3 ft. of growth per year. Yields vary from 20-50 lbs. per tree. We are using seedlings from this group to replace other less vigorous selections on our farm as a way to upgrade our orchard using open pollinated hybrids. Height to 60-80 ft. Hardiness -30 ...°F.


Here's another resource for you-
https://www.acf.org/

biwa
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I read somewhere that the chestnut disease doesn't affect the tree's roots. I thought about it and the only difference I see between the roots and the rest of the tree is that the roots aren't in open air and aren't exposed to sunlight. So the disease must either need open air or light to propagate.

So maybe I could just spray something soft on the main trunk to protect it. Perhaps an opaque silicone or latex caulk.

Is there any reason why spraying silicone or latex on the trunk would damage the tree?

TheLorax
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Try to think of a tree's bark as you do your own skin. If you were to paint your skin with a non-permeable coating, you'd be in trouble. Same thing is going to happen to the tree if you try to spray it with a non permeable coating, it's going to be in trouble.

Sure, we've all seen trees in people's front yards that have been painted white about 6' up the trunk but... they didn't paint the whole tree and they didn't repeatedly apply coatings every few weeks as the tree grew. As an aside, I'm told this was a way for people who routinely consumed too many adult beverages to find their way home to their own house. I guess it sure would make one's home easy to spot in the dark when one's headlights shined on all that white paint.

Here are a few sites to help you understand better why Chestnut Blight is so deadly-
https://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/Cryphonectria_parasitica.htm
Excerpt from above-
The blight fungus is carried from tree to tree by small animals and insects, who pick up and transport the infected spores from tree cankers on their feet, fur, and feathers. The disease is also spread from tree to tree by weather elements such as wind and rain. Spores from an infected tree are lifted by wind or carried by rain to a healthy tree, entering it through cracks or wounds in the bark. The spores multiply rapidly and give rise to sunken cankers that expand and kill everything above the canker--usually in one season. It has been observed that a chestnut tree can die in as few as four days after being infected with the blight fungus.
Tom Volk explains things so well-
https://botit.botany.wisc.edu/toms_fungi/may98.html
excerpt from above-
Cryphonectria parasitica is a fungus that invades the tree through wounds of cracks in the tree's bark. Once the tree has been invaded, the fungus grows through the vascular cambium of the tree, eventually girdling the tree and killing it.
Nice diagram of the life cycle of the disease-
https://chestnut.cas.psu.edu/PDFs/cryphonectria_life_cycle.pdf
Technical-
https://www.forestpathology.org/dis_chestnut.html

So as you can see, it doesn't really matter whether the roots are immune to the disease or not. Once a spore makes its way in, it's pretty much over for the tree.

So sad.

anntaylor
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If we use green house then this fungus can't be on our trees am I right?

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Kisal
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Spores are very small and can be carried on the wind. Greenhouses require ventilation. I think if the spores are in the nearby area, they could get into a greenhouse. JMO. :)

thanrose
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Absolutely not right.

One, it would be nigh impossible to grow a mature chestnut in a privately owned greenhouse. Two, the spores from the fungus would still be in the air that entered the greenhouse. They may lie dormant in the soil outside, but spread through air as well as direct contact.

Edit to add: Hiya, Kisal!

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Kisal
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@ Thanrose ... [img]https://smileys.on-my-web.com/repository/Others/others-015.gif[/img]



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