Heartnut

Will black walnut pollinate heartnuts?
I also saw that some states do not allow heartnuts to be shipped in. Why is this?
Does anyone have any experience with heartnuts in Colorado?

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No, black walnut does not pollinate heartnut.

You will probably not grow tomatoes near a black walnut tree. I remember a student asking a hort-sci professor why her mother could never get tomatoes to grow on their property, and the first thing she said was, “Do you have any walnut trees on your property?”. She mentioned juglone, and I seem to recall nightshades being very susceptible.

This might be helpful

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I planted a September fuji apple in 2017 inside a wire enclosure where a northern Carpathian walnut had died. Later, the walnut leafed out after all. I never got around to transplanting the apple tree, which is about 18 inches from the walnut. So far so good, but should I still try to transplant the apple tree? I don’t think the walnut would transplant well.

All walnuts produce juglone which is allelopathic to many plants including tomatoes, potatoes, and quite a few hardwood tree species. The black walnut group (Nigra,Californica, Hindsii, Major, etc) produces the most juglone. By comparison, Ailantifolia (heartnut) produces about 1/4 as much and Regia (Persian) produces about 1/5 as much. Even though they are significantly less, they still affect susceptible plants. IMO, it is best not to plant any type walnut tree near fruit trees.

I have not really looked into hickory species producing juglone, but suspect they produce very little or none. This is based on observations of maple and hickory trees growing side by side for years. Some maple species are very sensitive to juglone.

As an aside, the heartnut form is just a variant of the normal rounded Ailantifolia. Heartnut has been propagated much more in the U.S. than the normal round form. It is worth mentioning that heartnut is highly susceptible to walnut bunch disease. This is the reason it is not planted very much. I have a couple of heartnut trees grown from seed I got from Fred Blankenship in 2005.

Juglans Cinerea (Butternut) and Juglans Ailantifolia (Japanese Walnut) readily hybridize. Les Wilmoth had a large tree that produced an abundance of hybrid nuts.

You can group walnuts roughly into three clades with Persian as one clade, Japanese and butternut as a second and the black walnut group as the third. Persian will hybridize with both the black walnut group and with the butternut group. Black walnuts generally won’t hybridize with the butternut group.

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Thank you so very much, Darrel.

Dax

I have seen them for sale in nurseries but do not really know of any that are free standing trees. Black walnuts do pretty good here on the western slope but on the eastern slope we have thousand cankers disease as well as emerald ash borer, new invasives that threaten them. They claimed we would lose all our walnuts but so far its only older or weaker trees that are dying off en masse.

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Do emerald ash borers attack Carpathian walnuts?

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Yeah i would realllllly love to know that too. I started a bunch from seed for timber purposes and now im not sure it was the right choice.

According to USDA, it hasn’t been observed on anything but Fraxinus in the US, but has been known to attack Juglans and Ulmus in Asia. This document from Invasive.org details some studies where they looked at host preference for EAB. It sounds like it’s capable of infesting other species (including walnut), but that it doesn’t usually go as well for the borers. Neither source specifically addresses Juglans regia, but it’s probably not a serious threat. Walnut twig beetle, on the other hand, sounds like a real threat for Juglans. Just came upon that while looking for sources to refute or confirm my understanding of EAB being ash-specific.

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I am looking for heartnut seed to plant, anyone have some or could recommend a good source?

@JesseS
Try ;
Red fern farm
Grimo
Nut trees net.
Route 9 coop

You may be late this year.
Or maybe someone has a bag full ?
Not much of a crop here this year.

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I have a 20yr old jewel box heart nut.
For years it only had a black walnut to pollinate it.
Yet it has managed to have a few nuts, not many.
This variety cracks out in one piece !
Just a gentle crack, and the whole meat falls out whole !
The biggest problem has been late frost , killing the blooms.
It blooms early .
This year I had a good bloom on it, as well as on some younger heart nuts, no late frost, yet no nuts
Maybe next year.

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Who knows which heart nut varieties are later to leaf out / bloom?
I have heard that some are latter and can often avoid late frost.

I just got my St. Lawrence Nursery catalog and they are offering , for the first time, heartnut trees that have shown promise in their zone three nursery.

I’ll share mine with you, Jesse.

Dax

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I can’t remember where I found my information, but I made note of Canoka, Rhodes, Frank, and Stealth because I read somewhere that they were late vegetating. I think Cliff sells scion wood for two or three of those four.

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@jerry63 & @Hillbillyhort

This is a verbatim from Fred Blankenship’s observation:

" 9-1-19 Fred Blankenship writes about heartnuts: “Locket is later (bearing) and Imshu, Adelphia is first. Simcoe appears to be right behind Locket in Maturity; it has ten nuts, 4 & 6. Simcoe has late pollen. It could have pollinated Locket, which has a fair crop for a second producing season; lots of 8 nut clusters.”

Remember guys that Locket has the rich flavor of black walnuts and is unlike any heartnut I’ve tasted.

If those guys breeding black walnut into Carpathian/English/Perian walnut Juglans regia had found a wild specimen or specimens of the much more rounded Japanese walnut _Juglans ailantifolia, the parents of Juglans ailantifolia var. cordiformis for richness that it along with the entire span of Juglans nigra: black walnut possesses. they might have had luck in procuring a Carpathian style walnut with that richness they were trying to breed in. Now with “gene editing” they will find the specific gene and be able to do all of this on on a glass slide. CRISPR Gene Editing technology…

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Yeah it seems Im definitely wrong about the EAB on the Black walnuts its just Walnut twig beetle. What is confusing is anywhere with EAB there is a quarantine on walnut also where you need to “burn it where you chop it” or you need to have it milled in the county or city it was located in which has been hard for all the walnuts and ash that have come down as they are works of art. Boulder where the EAB was first found in CO also has a federal quarantine on Ash and Walnut. So i think i just inferred that but at the denver botanical gardens there is a EAB information hub thing and i will see what it says there. Any wood that basically isn’t pine or does not have its bark showing is not allowed to be exported as well from 3 counties.

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