Persimmon hardiness trials at Threefold Farm (6b/7a South Central PA)

General Fruit Growing
#1

Hi all, I’ve been growing out persimmons for several years now and have collected and grafted quite a number of Asian, American, and hybrid persimmons. We’re in a bit of a weird spot here. Most winters we’re technically a zone 7a, with just a few nights in the single digits. However, we’re rather cold when compared to other 7a climates like parts of Virginia. This winter, for instance, we hit around 2F, but also stayed cold enough that quite a number of folks were able to go ice skating. We’re also in a very exposed location with many trees cleared off for field crops, so wind plays a HUGE role in hardiness of plantings here. As a result, it’s a pretty good test area and some cultivars seem to experience damage that wouldn’t otherwise, I believe due to the exposure of winds.

I went around to all of our trees today. Some are out in a commercial orchard type setting, others are planting against buildings for a little protection from the winds and perhaps small microclimates. I’m going to list out cultivars by location and the amount of damage I saw on them. Since this is a rather long list, I also want to draw out some observations because many cultivars are planted in a few locations. Some had no damage at all, while other experienced significant damage. Why the difference? I have some thoughts that I’d welcome feedback on.

Wind - Exposed to cold & dry (and therefore desiccating) winds has a very significant impact on damage. Wind protection has a huge impact on the degree of damage to marginal varieties (for us, the pure kaki varieties).

Graft Height & Rootstock - Nearly all of our plants are on virginiana roots. Our initial practice was to nearly bury the graft, with the thought that if the tree was damaged, it may have a better chance at growing back from the roots. Persimmons seem to be really good at forming new buds in the situation where damage occurs, so many would grow back from the base. What I’ve seen though is that a high graft seems to add to cold protection if a variety is somewhat borderline. Why? As an educated guess, I think the height of the graft may increase the influence of the understock, perhaps placing the plant into dormancy earlier and delaying the waking-up process. I’ve noticed that higher grafts tend to wake up at least 2 weeks later than a low-grafted plant. This helps with the late frosts/freezes we’ve had lately. I’ve also noticed what seem to be genetic differences between seedling stocks, where some stocks right next to one another (we often planted 2 rootstocks in the same hole to be able to graft to both) wake up 1-2 weeks apart despite having the same scion variety on top. Again, this is just a few years of observation, but moving forward I’ll be grafting all kaki and hybrids at around knee high to delay the waking up process and perhaps enhance hardiness.

I’ll follow this up with a reply with my data from the orchard.

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#2

Here’s my data by planting location. I’ll try to summarize each area to help explain cultivar-specific differences in amounts of damage.

My levels of damage are listed in increasing order as follows:
No Damage → Tip Dieback → Branch Dieback → Dead to Ground/Graft

KHG = knee high graft

Nursery Beds - VERY exposed location, nearly all low grafts with exceptions of new grafts

Fire Crystal - Dead to ground
Hao River - Dead to ground
Hira Tanenashi - Major branch dieback
Gwang Yang - Dead to ground
Sung Hui - Major branch dieback
Giboshi (new graft, KHG) - Tip damage
Kyung San Ban Si (new graft, KHG) - No damage
Sajio (new plant) - Dead to ground
Picudo (new plant) - Dead to ground
Nikita’s Gift (new plant) - Branch dieback

Berry Barn - Exposed with minimal protection, similar to nursery beds

Early Jiro (new plant) - Tip dieback
Maekawa Jiro - Dead to ground
Great Wall (this plant has always struggled, low graft) - Dead to ground
Miss Kim - Some tip dieback, but important to note that it was okay with little to no dieback after a previous -5F winter (wind influence?)
Nikita’s Gift - No damage
Rosseyanka - Some tip damage due to late growth flush

Goat Barn - Mostly wind sheltered

Chocolate - Branch damage, though some fruit buds seem to have survived close to the building
Inchon - No damage
Korea - Branch damage, low graft
Picudo - Branch damage, may be a hardening off issue
Sheng - Tip damage, minimal
Gil Ya - Branch damage, in a very sheltered location
Rosseyanka - No damage
Fuyu - Essentially dead to ground
Hachiya - No damage, on lotus

Garage - Mostly exposed to north and west winds, but has a bit of vegetative wind cover

Saijo - No damage
Jiro - Tip damage
Miss Kim - No damage
Great Wall - Tip damage, minimal
Sheng - No damage
Gwang Yang - No damage

Protected Garage Planting - Very sheltered from the wind, may be a small microclimate

Tae Bong Si - Tip damage, branch damage, most damage occurred to exposed branches, some fruit may still form on protected wood
Gil Ya - Some tip damage, branch damage, may still fruit on more protected wood

Persimmon Test Area - Elevated area of orchard, mostly exposed

Kyung San Ban Si - No damage
Maekawa Jiro - Tip damage
Nikita’s Gift - No damage
Picudo - No damage on some limbs, branch damage on others
Kasandra - No damage
Korea - Branch damage but some fruit buds may have survived
Kasandra - No damage
Rosseyanka - No damage
NB-02 - No damage
Inchon - No damage
Miss Kim - No damage
Sheng - Branch damage, some branches may still fruit
Sung Hui - No damage
Gwang Yang - Dead to ground
Saijo - No damage
Steiermark - Minor tip damage, young plant

Main Planting - Slightly sheltered from wind due to positioning on property, also slightly higher elevation-wise than most other plantings

Ichi Ki Kei Jiro (whole row) - No damage to tip damage, some branch damage, all are low or buried grafts
David’s Kandy - No damage
Dollywood - No damage
Maxum - No damage
Journey - No damage
100-46 - No damage
Mikkusu (JT-02) - No damage
Il Jae Mok Cha Rang Tam Kam - No damage
Jin Yong Tam Kam - No damage
Cheong Pyong - No damage
Chibacha - Dead to graft, new graft
Mt Roman Kosh - No damage, last cultivar to push out
Mt Goverla - No damage
WS8-10 (Barbra’s Blush) - No damage
Kasandra - No damage
NB-21 (Sestronka) - Branch damage
Sung Hui - No damage
Jiro (whole row) - Highly variable, mostly dead to ground, low/buried grafts
Chuchupaka - Dead to graft
Saijo - Low grafts are dead to ground except high on the hill. KHG have no damage and leaf out much later.

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#3

Thanks for sharing! You should also try Chinebuli, I’ve had it for a few years over here with zero injury.

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#4

Good report !
Thanks

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#5

Great report.

My minor added note: I remember an observation that Cliff England grafted his persimmon trees high. I can’t confirm, except that the one persimmon that I purchased from him (Kassandra) is grafted at roughly 2 1/2 feet. I’ve never had any damage on this tree. Maybe his grafting technique helps explain his results re the cold hardiness of varieties.

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#6

@ampersand – Does your Chinebuli have a high graft or low? I know that England reported it to be cold hardy. But then I’ve seen others commentary suggesting that Chinebuli is a synonym for Jiro, which isn’t so cold hardy. I have seen reports that he grafted high. I’m wondering now if the results for Chinebuli could be related.

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#7

It’s a pretty high graft, ~20".

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#8

Your Saijo results seem very inconsistent with some dying back to the ground and some surviving with no injury? We are 6B and lost all Saijo, all were low grafted though. Interesting observations, I might try grafting Saijo with a ladder next time!

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#9

Nice inventory of persimmons for trials. Did you buy all the persimmon trees or you grafted yourself? I thought I finally found JT-02 that could withstand my Z5. It survived to -23F then come the Polar Vortex that brought the temp down to -31F and killed 20 of my JT-02. Only 2 survived. I potted them up this year and I will plant them at my new house and bury the graft union below ground level for insurance to resprout if the -31F comes to town again.

Tony

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#10

Great report Tim!

I could have used the exact words of this paragraph to describe the last winter at my new property in Sandy Hook, CT! Hence, your notes are perfectly relevant for me…

This is very good news for me, as I am interested in this variety!

Did you mean to say “Sheltered, except from a bit of wind” ?

This is also good news, as I already have a Tam Kam, which I just put in ground, but was thinking of protecting it the next couple of winters.

By the way, what is the difference between these two Tam Kam trees?

Same here, I got two trees from Cliff last year and the graft union was pretty high, close to 2.5-3’ high, but he didn’t give me a good reason for that when I inquired about it, he just said that I can’t plant a persimmon tree too deep, and the deeper the better.

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#11

This is too cool. I’m zone 6a, so there is no need to bother dealing with Asian Persimmons here.

I have a follow up question that is more relevant to me and others too, perhaps.

Do you have a general ripening order of your American varieties and also jt-02 and Kasandra?

Appreciate your time!

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#12

Our Saijo kicked the bucket, too—dead to the (low) graft, in a semi-protected area on a southern slope. (EDIT: This is 6b Kentucky.) It grew beautifully last season (its second one here), showed no signs of sickness—and the winter lows weren’t too bad: I think we got down to 2 or 3F once, but that was the worst of it. I’m getting ready to try reworking the virginiana rootstock over to JT-02.

Ichi-ki-kei-jiro in the same location did fine: no damage and is now waking up. A little higher graft than Saijo—maybe 10" or so. Nikita’s Gift and Rosseyanka, in a more exposed location, also look good. They took some damage last year–Nikita in particular—but from a late spring freeze and not winter. Fortunately, the spring freezes weren’t too bad this year. My Rosseyanka has had some leaf and stem anthracnose that I think may have been aggravated by late freeze damage. I sprayed oil and copper—dormant and delayed dormant—this spring, so we’ll see how that goes this time.

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#13

One possibility – Research on persimmon hardiness shows that trees are much more hardy when deeply dormant (e.g., Jan) than when starting to wake up (e.g., March). A southern slope – facing the sun – could encourage early emergence, making the tree especially vulnerable. The ideal location for a sensitive (maybe early emerging) variety such as Saiyo would be a Northern slope that is sheltered from the low winter sun but exposed to the high spring / summer sun.

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#14

Good to know! I have one that I’m putting in this year, though it’s a relatively low graft. I’ve heard good things about it, so it’s good to have input from a fellow Pennsylvanian!

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#15

Agreed, the results are very inconsistent. The main differences seem to boil down to the high graft and the amount of wind exposure. I will probably allow the low grafts to die, then re-graft high onto root sprouts.

#16

Agreed. My working theory is that the higher graft on a hardier stock causes the plant to go into deep dormancy sooner than it otherwise would and/or delays the waking up period until later. It’s interesting to see the differences between seedling virginiana rootstocks, even when planted side by side. It would be interesting to have a seedling source of stocks that were very late to leaf out.

We have a similar situation with sugar maples we planted on our property. Some are relatively early to push out, others are just now swelling buds. Because we’ve been so prone to late frosts/freezes, delayed break from dormancy is really important to me.

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#17

No ripening info just yet. Hopefully in the next couple of years. I do have some information on which varieties are earliest versus latest to push out in the spring. That’s really important for us because of the tendency to have late frosts/freezes. In our experience, most persimmons don’t do well with a late frost after they’ve passed a certain phenological stage.

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#18

Yes, it’s interesting to see which do well in our marginal climate. There are a handful of pure Asian varieties that I have high hopes for but the hybrids are a much surer long-term bet here.

I’m not sure of the difference between the Tam Kams. I got them both from Cliff and while they set some fruit last year, I believe they dropped all of it.

I corrected the “sheltered” terminology that you mentioned, sorry for the confusion.

I’ve talked to Cliff about high grafts as well. I gather that he’s primarily concerned with the survival of the trees themselves, so I think that’s why he advocates low grafts: in order to preserve the variety in the case of a catastrophic freeze event. However, high grafts, in my limited experience, do seem to overwinter better in a “normal” winter and the delayed dormancy break seems to be helpful in our temperamental springs.

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#19

Thanks for the reply! Do you have a favorite or maybe top 3 Americans that you like best? Sorry for hijacking your hardiness thread. It’s just rare to see someone have so many cultivars.
Thank you!

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#20

How did the 20th Century and Mazugata do or did you not plant them yet?