@mikatani, another question. Have you had fruit from JT-02 or Chuchupaka in your location?
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Short season growing season for persimmon would be 180 days (59°F +) but within this timespan there are 75 days with possible 77°F+ temperatures and effectively 250 hours of 77°F+.
A long season would be 200 days of 59°F+ and effectively 400 hours of 77°F+.
The most important aspect is the heat hours (1 hour 77°F+). If within a short growing season the amount of heat hours is attained then sugar development will be OK. But this is rarely the case…
Need for heat hours also depends on variety and some will develop enough sugar even with a lot less heat hours. there are few varieties that will develop enough sugar with less heat hours. All non-astringent kaki varieties for example will need a lot of heat hours and will taste bland when lacking heat hours.
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I recently planted JT-02 so I have no experience yet with this variety.
Chuchupaka is late ripening and has a high need for heat hours.
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LOL – If 180 days >59 F is a short season than I’m SOL! My last frost in spring is generally in late April / Early May. My first frost in autumn is generally late Oct / early Nov. In between there are 6 months (May through October) or roughly 180 days. There’s no way all those days exceed 59 F.
On the other hand, a total of 75 days >= 77 F may be attainable. So far this year Providence had 8 such days in May, 19 days in June, 31 days in July, 30 days in August, and 9 days in September – a total of 97 days through 9/15. My location may be slightly cooler. But then I could pick up another 10-20 days before the end of October.
FWIW my IKKJ are starting to change color.
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@Mikatani – A follow-up question, if I may . . . .
I like these temperature guidelines. They resemble in form (but not specific substance) some guidelines that I put together myself for ripening figs. Figs require less heat (>65 F seems sufficient) but more days (90-130 are required, depending on variety).
Did you develop these guidelines yourself or do they come from some published research? If so, can you post a link? Thanks again.
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You will not find this info anywhere I think. It is from 30 years of experience that I drew my conclusion about the need for heat hours. All research is based on hours of sunshine and simply assuming that temperature is a negligable factor. So as far as I know no research has been done on this subject. This is perfectly understandable since commercial persimmon growing is always done in areas that have perfect persimmon climate. An good example of the importance of heat hours is persimmon production in New Zealand. New Zealand ha a long growing season and it does not have really low temperatures but neither does it have really warm temperatures and these warm temperatures are needed for sugar production. I don’t know if you have ever tasted New Zealand persimmons but they are just slightly sweet, just enough to make them palatable. Compared to persimmon grown in Spain or Israel where heat hours are plenty, these persimmons really lack sugar.
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Why avoid TyTy Nursery? I was looking at their persimmons but would like to know your opinion, as I am new to fruit trees. Thanks!
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Quite a few on this forum have not been pleased with the health of their trees.
I bought 6 trees this spring, 5 plum whips and one larger cherry. 3 of the 5 whips never budded out. The cherry popped a handful of leaves and died over about 2 months.
All 6 trees arrived with no visible buds on them.
I’m now growing out rootstock to graft the plum whip replacements myself.
I got store credit so well see what I get next week spring.
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They have a long-standing reputation for selling trees that are mislabeled at best, low quality, and wildly unacceptable customer service. The few times I’ve looked at their website it screams “deceptive business practices.” Reviews so bad they almost sound made up, but I keep hearing them from sources I trust. Wouldn’t touch TyTy or their sister companies with a 10 foot pole.
Just to be on the safe side, I’m extra cautious whenever I see a nursery out of Georgia. TyTy does business under a number of names, but it’s always of Georgia.
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Hi guys.
Curiously, I grafted that variety (among others) this past spring onto Diospyros Virginiana rootstock.
The cuttings come from the IVA germplasm bank (Valencian Institute of Agricultural Research).
This is the germplasm bank.
https://ivia.gva.es/es/banco-de-germoplasma-de-caqui
And this is the descriptive sheet of Ichikikei Jiro translated into English.
DK040-ICHIKIKEI-JIRO-IVIA-16 (2).es.en.pdf (335.7 KB)
Very good variety
If you like good persimmons try to get this variety
Tardive de Charente
Descriptive sheet translated into English
DK058-TARDIVE-DE-CHARENTE-IVIA-16 (5).es.en.pdf (402.1 KB)
Regards
Jose
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I was looking at daily normal temp graphs for our areas, and most days from about mid-April to late October have average highs over 59. I feel pretty confident that we get in the range of 190-210 days with highs over 59 in most years.
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Weather Spark has decent graphics for that as well…though of course those are 30 year averages and don’t hold up for any given year.
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Weatherspark is OK, but this source is much better for sussing out weather/climate metrics related to agriculture.
https://agacis.rcc-acis.org/
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When I read “sussing” I expected your location to be in the UK.
Thanks for the link. I’ll check it out.
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@Shibumi @jcguarneri
Thank you both for your quick replies, and apologies for my slower one. I really appreciate the information and will be avoiding TyTy. This forum is so great to be able to share this kind of knowledge. Thanks again!
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I’m not convinced.
A growing season that extends from start of April through end of October would be 214 days (7 x 30/31). If we chop off the 1st two weeks of April and the last week of October, were down to ~193 days (21 fewer). So far so good.
Now the key question is how many those 193 days have frosty weather, especially at night. It seems common to see frosts here in late April/early May and also mid October. This year, for example, most of New England had a severe frost in mid-May. And if the night time temperature is 28 F, it doesn’t seem to matter how hot the day is.
So let me ask you to check a slightly different metric: How many days do we have with (1) a daytime temperature above 59 F, and (2) no intervening day with a temperature, day or night, below 32 F?
Even this is probably a generous statement of the problem. With figs, I find that growth stops and the season resets if there are 2-3 days when temperatures drop below roughly 35-37 F.
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The start and stop of growing season seems hard to determine much like when to start and stop chill hour accumulation.
I guess it varies by type of fruit tree and much more on temperature and duration.
I think we’re never going to get a better estimation beyond finding out how a variety actually behaves on our land…and even that will change from year to year.
Where I am I’m content and even expecting to miss years producing fruit as we can get very warm winters compared to the 30 year sliding averages.
I’m sure we all know the variability of what does into generating an average.
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I agree. That’s the one part I’m not sure about. I suspect a light frost doesn’t matter as much as it would to a fig, as the persimmons are clearly starting to wake up before the last frost. Somewhat at random, I looked at 2016 data for Nashua and counted about 170 days with highs of 59 or above between the first and last frost days for that year. Still a bit shy if that’s the criteria…
@Mikatani is your temperature criteria restricted to the period between frosts?
Looking at the big picture, though, clearly @SMC_zone6 is able to grow a variety of persimmons that he’s satisfied with, and he’s more or less at the midway point between us.
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Yeah, you could be right that some trees might shake off a frosty day in May. But I just don’t have enough confidence in persimmons yet.
Reality keeps me humble. Right now I’m sitting with a friend in his living room in Rutland VT. Two years ago, we planted Illinois Everbearing mulberry here. It leafed out this May, just in time for the hard frost on (as I recall) the 17th. It is now stone cold dead.
If we can’t keep a fairly hardy mulberry alive through a mid-May frost, what can we expect from an Asian persimmon?
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Man, I hear ya. Last winter was brutal on just about everything. My persimmons were about the only thing stubborn enough to wake up at the normal time.
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