Giant Chestnuts


Grafted chestnut tree can produce fruit in three years.


So a nursery bought tree will produce the following year after planting?


Generally chestnut grafts do best on the most closely related rootstock but that’s not always true. I have had failed grafts on closely related stock and successful grafts on stock that is not related at all. Szego is mostly Chinese x Japanese and sometimes grafts well on Chinese and sometimes grafts well on Japanese.


I didn’t do anything to my chestnut seedlings so far. I want to wait till seedlings grow bigger, then I can try multi-grafts to see which varieties can do good on it.


This is from an article I read about 15 years ago. Please look it up and verify. There are 4 ecotypes of chestnut. Grafts fail if placed on the wrong ecotype. This is the reason why seedlings of Qing are most often used as rootstocks for Qing. The probability of a given variety’s own seedlings being the right ecotype is much higher than for unrelated seedlings.

I will speculate that there are more than 4 ecotypes but that was not in the article I read.


You could always just try several different kinds and hope for the best. The rule of thumb around here is that if a graft leafs its fifth spring, it is a lasting combination. Sometimes they fail the second or third spring here. I’m pretty much at the northern limit for american chestnut, 110 frost free days, fluctuating temperatures, so that might not hold for all locations.


There’s a 1988 study by Santamour that reaches that conclusion, that chestnut trees with different cambial peroxidase isozymes will not graft to each other. That study was somewhat limited in scope. It was shot down by a better, longer study performed in 1994 by Hongwen Huang.

It’s not clear why Qing frequently has graft union failures, particularly delayed graft union failures. Despite the fact that Qing is treated as a pure Chinese tree, and looks like a pure Chinese tree, I suspect it’s actually a hybrid of some sort, possibly a mollissima/pumila hybrid.


castanea, Thank you so much for all this great information. I could have saved myself a few weeks of research if I had found you/this thread sooner! I am in Zone 5b. I have a Dunstan Chestnut and want to add a couple others. Which do you like best for flavor - Jenny, Qing, or Szego? I would love to get a couple seeds of your Nanjing Select :slight_smile: also to try. If you would be willing to send them please let me know and I can send you money for shipping. Thanks again for the help and wealth of information!


I am all out of seeds for this season, Send me a message in August and I’ll send you some.

Jenny, Qing and Szego all have good flavor but they’re all different in flavor and tree vigor. Qing will probably die or at least the graft will die in zone 5. Jenny and Szego graft more easily, are more cold hardy and much more vigorous than Qing. Grafted chestnuts trees do not tend to do well in the colder parts of zone 5. Better to plant seedlings.

There’s also a Facebook chestnut group called All About Chestnuts.


In order to solve the delayed graft union failure problem that Qing often has, can you bury the grafted tree deep so the graft union is buried? Almost everybody says that you ought to bury a transplanted tree the same depth that it had been planted previously but my eccentric uncle insisted I plant some trees (plums, lilac bushes, and a chestnut seedling) deeper (a lot deeper, between a 1 foot and 1.5 foot deeper) and none died. I think they struggled the first year but after that they have been very vigorous growing trees. It makes sense that if they survive then they will have very deep root systems. Just an idea…


It definitely can work. I have one tree that is planted with the graft union beneath the soil and it is doing well. It works better when the graft union is not very high on the tree and when the soil is very well drained.


Does the graft root above the union or is this only done to insulate the graft from the dry, cold wind?


It would, with time, root about the graft. Not done to protect against the winter.


instead of starting a new thread , i thought i would ask here. i want to try chestnuts up here. I’m in z3b/4a. anyone know of a cold hardy cultivar that would survive in my area?. don’t need bumper crops . just a decent amount of nuts. in Maine so it would have to be a blight resistant cultivar. thinking the chinese would do best up here. any thoughts?


Moose, there are Dunstan hybrids growing north of you, seedlings of Chinese and American heritage.
There is a nursery in Springfield New Brunswick who grows them. I have an unknown Chinese hybrid on the north shore of Prince Eward Island, so also probably north of you too. I should add that PEI doesn’t have blight yet, so I grow the American ones too.


thanks! thats good to hear. ill look to see who sells Dustan here in the states. i have a cousin thats a marine biologist that lives in PEI. married a girl from there.


@castanea do you have any information regarding how well Badgersett timber type chestnuts peel and their flavor?

Thank you,



Dunstan hybrids are notorious for their relative lack of cold hardiness.


Try a seedling of Luvall’s Monster or Qing from Red Fern Farm in Iowa.


Nut quality of the Badgersett hybrids is highly variable as is their resistance to blight. And unfortunately there have been numerous complaints of Badgersett failing to fill orders in the last couple of years.