Dooley Hybrid Walnuts - Pollination and Hardiness

I’ve been toying with the idea of adding a black walnut in the back yard as we have lots of wild trees around to pollinate. Lately, though, I’ve been attracted to the Dooley 69-E Persian/black walnut hybrid, but I’m not sure if it will work for me. My questions are:

  1. Will black walnut pollinate this adequately?
  2. I’m right on the 5b/6a line (realistically, I’m probably 6a from being in town). Is this likely to be hardy?
  3. What are the heat requirements for properly fillling the nuts? I’d hate to grow a tree out only to have it fill nuts only once every few years.
  4. Is it actually any good?

The most complete source of info I’ve found so far on this is Grimo Nursery. While I’m sure they know what they’re talking about, they only mention pollination relative to Persian walnuts. Also, they list this as 6a, but they seem to err on the conservative side for hardiness ratings looking at some of their other products.

@Fusion_power @Barkslip @Lucky_P


I had to look it up to find out what it is. Grimo also sells seedlings from it. Based on the pictures, this tree is NOT an F1 hybrid of Nigra X Regia. It is more likely an F2 crossed back to Regia. Why? I’ve seen a few dozen F1 hybrids and every one of them show black walnut traits.

Pollination would probably be better if you had a protogynous tree like Thomas nearby.

Side note, I looked at Grimo’s photo of Thomas nuts. That is not Thomas. He may just have the wrong photo or it may be the wrong variety.


Thanks! Thomas is the variety I’d likely get if I were to go with a straight nigra. Do you have any photos of the nut? Most of what I can find for pictures/videos/etc comes from TyTy, and I wouldn’t trust their info any more than their plants. I’ve read that it cracks well, but I’m assuming it would still need one of the heavy-duty crackers.

As for pollinators, I would only have room for one tree. However, there are at least 4 wild black walnuts in a 400’ radius from the planting site, and maybe another half-dozen at 1000’. I haven’t investigated to see whether any are protandrous or protogynous, but I’ve seen each one set a good crop of nuts (the specific trees will vary from year to year), so I assume there’s a good mix. My biggest problem is likely going to be the preponderance of squirrels.

I have this picture which includes a Thomas seedling. The seedling nuts are 95% similar or more to the Thomas parent. Bottom center 2 nuts are the Thomas seedling.


Don’t mess with the hybrid. My friend has them and they are novelty after growing them for 30-40 years he learned.

If you don’t have a Thomas planted by next Fall, I’ll send samples of 8 or 10 b. walnuts including Thomas so you can taste several different profiles.

Heartnuts and Persians (most ALL) are completely hardy for my area of 5b in IL. Grimo has always jacked up the cold-hardiness on all his trees for I don’t know reason(s).


Good to know, thanks! I might have to take you up on that offer.

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Cool. It’s the same routine (most) years and this b. walnut arboretum of sorts of grafted trees is right on the way to every other nut tree I visit. It’s just that I don’t eat black walnuts, myself. But, a simple stop it is to collect them.

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That sounds like a great resource to have nearby! What I’d really love to do is plant a named hickory or a northern pecan cultivar. But, only room for one, and I haven’t seen any hickories within half a mile.

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You just bark graft (you get up on a ladder) another hickory cultivar at a side branch coming off the canopy area when the tree is like 10’ tall or 15. You rest a ladder up against a 15-20 footer and let it swivel a bit while you climb if necessary. But, that’s how you do it.


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Get a Selbhers shellbark hickory. It’s self-pollinating, is prolific & precocious. It will give you a dozen nuts a year when it starts bearing I’ve now seen the last two years. It’s gonna need a pollinator. You got think about that as time goes on. It will bear in 5-6 years as a bark graft vs any other hickory that may take more than 20-years. It’s just crazy how and why/when hickories decide to be fruitful. There’s no rhyme to it and some guy might wait 12-years as an example for a ‘Grainger’ shagbark; the next guy 15-years; and there’s some other guy waiting now 25-years and never saw a nut. ‘Selbhers’ doesn’t do that.

I’d recommend if you can to find a Shagbark that overlaps pollen with it. Someday, I’m going to have all that information available, but again, how long is that gonna take? I’m hoping others begin reporting when their hickories are in bloom on the thread I created on the group here for hickory pollination.

Pecans are very reliable to produce in 6 to 8 years.


Thanks! Those are the kind of “insider” tips I come here for. More thinking to do on this one…
The last two towns I lived in had pecan trees around that I could forage from. Not huge, but still a much better yield:work ratio than black walnut. I do miss that.


After reading over some of your other threads on pecans, I checked out my cooling degree days and it looks like in the last 10 years, it’s usually between 750-850, with a couple down in the 600’s. Does that leave a lot of options for pecan varieties, or are there just a handful that are going to work out? I know to temper my expectations on nut size, but I’m curious what my options are. Also, will you have trees available in the next year or two?

Bark will come along later and add more. Short version, you will have to use northern and ultra-northern varieties to get a crop. It is not just cooling degree days, but length of season that is a concern. You need varieties that will ripen in 160 days or thereabouts.

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Good point! I forgot to mention that part. In the last 12 years, the average is 167 days using base 32F, with only 3 years below 160. Being in an urban center makes me have to get creative and choosy on fitting things in, but it does help with the heat units and growing season!

use 28 F as a base, Jay. That’s your true growing season for tree crops.

And it’s looking as if Deerstand and Fisher are the two very best croppers for a friend of mine with 15-years in growing pecans at 900’ elevation in Humboldt (area) California. He’s been growing (must be) 8-10 of the earliest maturing varieties and is at the place where he knows to re-graft other trees over to Deerstand & Fisher. Both of those are producing real good every year. He said this year he didn’t have to buy nuts for winter for the first time for his family, and that his Cooling Degree Days (CDD) were the highest they have ever been at 905.

I looked at Wes Rice’s book last night to see if those are pollen compatible but they aren’t listed. I just checked @Fusion_power Pecan Pollination Chart and that info. isn’t on that yet, either. I cannot find that information Googling either.

You just need to confirm before you or anyone plants those two cultivars which pollen shed they are. Whether type 1 (protandrous) or type 2 (protogynous). You need a type 1 and a type 2 and that they overlap pollen shed. The dates for pollen shed is different for each cultivar and overlap can be full or partial or hardly any overlap.

No I won’t have trees, Jay.

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Dax, has your CA friend grown Warren 346? The other suggestions I have are Iowa and Lucas. Starking Hardy Giant is a 160 day tree.

Deerstand originated near Burlington Iowa. It has 101 nuts per pound with 52% kernel. Shuck split is 8 days before ‘Colby’ with good cracking quality. Nut quality rating at 2 is not quite as high as southern varieties but is excellent for a far northern variety. Deerstand is notable for having a combination of good traits though no single trait is outstanding. Source: Wes Rice

'‘Fisher’ is a native selection made by Jacob Fisher, New Memphis, IL. Introduced commercially in 1938 by Joseph Gerardi of OFallon, IL. Nuts are oblong elliptic with an obtuse apex and acute base, round in cross section. There are about 74 nuts per pound, with 48 percent kernel. Kernels are cream in color, with medium dorsal grooves and a narrow dorsal ridge. Tree reputed to be a heavy bearer. Ripens a few days after Starking Hardy Giant. Source: G. Wesley Rice

“Lucas” is a Seedling from Lucas Ohio in 1965. Lucas is protogynous, precocious, and scab resistant with 108 nuts per pound and 49% kernel. Nuts mature 10 days before Colby. Lucas produces decent quality nuts on a compact willowy tree. Lucas has a flaw that nuts will not fall from the tree at maturity. Very tolerant of cold weather, but susceptible to yellow aphids. Source: G. Wesley Rice

Warren 346 Origin: Native pecan tree found by Dale Warren in his native grove located in the Grand River floodplain south of Wheeling, MO. Warren 346 matures 27 days before Pawnee making it extremely early. It is scab resistant with a small nut that cracks well. The tree has upright growth habit that forms narrow branch angles. Source: Bill Reid

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@Fusion_power @Barkslip thanks again for all the info and recommendations. Heat requirements and pollination compatability of the ultra-northern pecans has to be some of the most arcane knowledge on the net. I’m sure someone knows protogyny vs protandry on those cultivars and hasn’t thought to report it. I feel like either people are already in a pecan growing region and don’t have to worry too much, or have enough land to try a bunch of types in the hopes that it will work out. Also, I’m sure fewer people are willing to roll the dice given the higher cost of trees, space requirements, and longer years to bearing as compared to say a peach.

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He’s going to write a thorough report from the standpoint of each cultivar. Once I have that, I’ll share it.

Warren was not one (I recall that) he had success with. Mullahy is not a reliable producer and he has problems with some nuts filling while others apparently did. Mullahy is a part of the history to him, now. It’s worthless. Lucas I believe is good. …and Gary Fernald always recommends Lucas to folks anywhere far up north like Chicago (cause it’s cooler there than where Gary and I are on the other side of the state) - or Gary recommends Lucas to those asking for his help in places like Michigan, Wisconsin, or Minnesota. And Gary recommends seed from Lucas to anyone want to try to grow pecans where the data isn’t known whether success will point in the right direction. So, I think you’re onto something about Lucas, too.

I asked my friend what his thoughts are for Fisher and Deerstand in ultra cold areas and he’s apparently going to write about that too come later.

I know that OC-6 aka one Gary calls “Meat” also when he cannot remember OC-6 and he’s sending off scionwood. So, “Meat” is in peoples hands and they should know it’s actually OC-6 from O’Connell Island off of the shores of Burlington, IA.

‘Iowa’ doesn’t crack and therefore should be abandoned. OC-6 has the same ripening day that Gary estimates to be ‘probably’ 135 - 140 for Iowa (135-days) to shuck split and OC-6 he simply says is 140-days. He says, ’ OC-6 is just a few days behind Iowa '.

I like OC-6! Gary likes OC-6! It needs to be in peoples hands. It’s prolific and bears good crops.

I hope we can put these puzzle pieces together. I actually am not sure just how much help his California data will be to another completely different climate like Chicago. (Is there any way to equate the two or not? I do not know.)


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One more thing for both of you guys is that New London County Connecticut (zone 6b) and the guy I sort of recall having around 800 - 900 CDD and a pretty long season of I’m going to say 185 to 220 days. Which is exactly what I have btw. That’s again using 28 F as the base point for Cooling Degree Day calculators, online.

His experience is as many years as my California friend. Mullahy produces every 2 or 3 years okay for him and the other years it pisses him off those years. His other selection after doing all his own research probably 20-years ago became… ‘NC-4’. That’s where it’s been just dynamite for this guy. NC-4 has produced prolifically and w/o hesitation, annually, of course.

I don’t know much more information than these two guys experiences.

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I’ve tried to equate a coastal maritime climate like CA with a mid-western or north eastern climate and found it difficult. The best thing to say is that I don’t know with enough certainty to make recommendations. I can say that either climate is challenging for pecan and only the shortest season varieties have potential.

I agree about Iowa which cracks in crumbles. I still don’t know for sure about Warren 346 because it has several reports of good production such as from Bill Reid. He lists it as Protandrous which I did not previously have. Northern Pecans: Pecan Cultivars

Bill also has comments about Lucas stating it is too small for propagation, however, IMO it still has potential in ultra-northern climates.

I will put a note in the spreadsheet about OC-6 aka “Meat”.

At this time, I’m going with Campbell NC-4, OC-6, Deerstand, Fisher, Lucas, and Warren 346 as most likely to produce in ultra-northern climates. This specifically means any climate with less than 160 frost-free days. I am keeping the mental door open regarding maritime vs midwestern climate.