Draft Wikipage on Growing Persimmon

Since a fair number of forum members have an interest on finding a way to determine in advance which Persimmon cultivars will grow well and actually ripen in their particular geographic region. I have drafted a proposed Wiki page that I hope to soon submit for approval by wiki links. Of course there is no guarantee it will gain approval for publishing, but if it does it would give those forum members who have first hand experience with particular varieties to share their data with other forum members who could then benefit from the data provided. For example: If I see data from a member who resides in a climate similar to mine who is reporting success in ripening, then I could use the degree day calculator to compare his climate to my local here in Kent, wa. If the degree days are close enough, then I could make an informed decision, rather than trusting a nursery’s recommendation.
So below is my proposed draft and I invite your suggestions for improvement. I hope to submit it soon for approval so that forum members can input data starting this fall of 2021.
Thanks for your constructive input:

Rough Draft Wiki page

On the forum titled Growingfruit.org, members share their fruit growing experience freely with other members. The topics vary widely and cover almost every fruit or plant life that one can imagine. A member desiring to learn about a new plant variety or who has questions can seek the advice of more experienced growers by posing the question and obtaining advice and suggestions from other more experienced members who often have personal experience relevant to the inquiry. This website services members worldwide giving members access to a wealth of knowledge and a treasure trove of expertise in grafting, propagation and production of fruits and vegetables.

I am proposing a wiki page that forum members can access to add their specific firsthand knowledge and data about a specific topic: “The Climatic Requirements for growing and ripening Persimmons”. The reason I would like to create such a wiki page is that there is a need for members wishing to successfully grow a given persimmon cultivar to obtain reliable data from others who have experienced success and are willing to provide data to others who may be considering growing the cultivar.

Like most other fruit trees, Persimmons require several years once planted to actually go into production. The majority of fruits can be grown with little regard for the climate, as long as the growing zone is respected and eventually obtain ripened fruit, not so for persimmons! If the climate zone and growing conditions for persimmons do not provide the length of growing season, and the degree days of heat and solar radiation required to actually ripen the fruit, one could plant a new tree, grow it for 3-4 years only to discover that the perfectly mature fruit it produces will not ripen before the onset of winter. So you could have a perfectly growing tree that never produces useful fruit! There are other types of fruits such as figs that need extended heat days to ripen. While this proposal focuses on the Persimmon, once it is understood, it could readily be adopted or modified to evaluate other types of fruit.

While plant Nurseries do provide some advice on suggested growth zone, they do not have the specific information to determine if any particular cultivar of Persimmon will do anything other than grow. Moreover, in spite of numerous articles on persimmon growing on the web, not one provides a calendar reference or zone map that is oriented to ripening potential for each cultivar.

There are a number of local forum members in my region near Seattle who would like to find an efficient method to determine which varieties of Persimmons will actually ripen in our somewhat short cool, maritime climate. Many have varieties that do not fully ripen, or never get fully ripened to be worth growing! I even know one lady north of me who constructed a canopy over her persimmon trees to provide the microclimate for her trees. A considerable investment in time and resource. As I have researched the subject there appears to be numerous Named varieties and hybrids that have been developed in northern climates, but it’s very difficult to ascertain their time of ripening and also pin down the climate by zip code so that one can make an efficient and accurate comparison to determine ripening potential for another location. The same is true for Asian varieties.

It would very productive if one could determine in advance which cultivars have a chance of ripening in a particular location, before selecting that cultivar to grow or graft over an unsuccessful existing variety.

So I am proposing a Wiki page where forum members who have and are willing to provide reliable data on any particular cultivar of persimmon (Asian, Native, or Hybrid) can access to contribute useful data to share with other forum members.

The page would be a simple fixed spreadsheet for entering the following information.

Source: This would be the members forum user name. For example my growing fruit.org user name is @Dennisd. Other forum members can use this information to contact the source to ask any particular questions.

City: Large City near the Source of data.

Zip code: Enter the zip code of Source.

Persimmon cultivar name: This would be the specific name of the cultivar for which the data applies.

Astringent vs. non-astringent: Enter type

Rootstock: Enter the rootstock name (D. Virginiana, D. Kaki, D. Lotus)

Age of Tree: Enter the Years the tree has grown if known, or approximate age if not known.

Date: (Month/Day/Year) The first date when fruit was ready to harvest.

Duration of harvest: Enter the number of days from start of harvest until all fruits were ready to harvest.

Condition of fruit harvested: Describe whether the fruit could be consumed immediately after picking, if it required additional time and procedures to fully ripen before consumption or any special treatment to overcome astringency.

Finally, if possible, it would be desirable to safeguard a member’ s data if editing the data could only be done by the Source of the data.

With the above key data it would be feasible to determine if the particular cultivar reported may be suitable to grow in another geographic location by comparing weather data and average daily temperatures to any other potential location. This comparison can be accomplished by comparing the cumulative degree days above a certain base temperature between the known location (location where growing and ripening successfully occurred) and any potential new location (where the cultivar is desired). The following free website can be used to obtain the cumulative degree days above the base growing temperature for Persimmon which is typically accepted to be 70 degrees F.

(Note: I would suggest this base temperature for Persimmon since most experienced grafters use 70 F as the minimum sustainable temperatures to begin outdoor grafting. ) Using this base in the formula on the following website you can generate the degrees days that were actually required from the current year for ripening to occur. The sum of this data “Da” (actual data) can then be compared to “Dd” ( data at the desired location) to obtain a statistical assessment of potential success. This comparison should be based data generated within the same timeframe for the actual reported and the desired growing sites. I chose the below website for its ease of use, simplicity and its applicability anywhere within the US. When using this website to estimate growing degree days, you need to use the “Cooling” button rather than heating to capture the actual heating data above the base temperature.


Dennis Dowdy

Kent, Wa 98030

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Could you explain that Degree day web site better
First I put cooling like you said but left it at 65
Second at 70
Here is what I got for a five year average what does it mean

65 degree F cooling
total 1071.1 estimated 0.3%
Fahrenheit based 5 year average 2016 -2020
cooling degree days with a base temperature of 65

Second at 70 total 589.2 estimate 0.3

Not sure what this even means Instead of reading the whole site , and try to figure out
what does this compare to yours ?

Do not ask me why but maybe also list other things that ripen to compare

For Instance In Aurora IL. it is 40 miles West of Chicago Altitude 718
Go a 45 minutes (50 miles South west) In Kankakee IL. (elevation of 656)
the mulberries ripen weeks after ours (maybe a month or 3 weeks)

Not sure why that is , but we have clay Kankakee has more gravel soil
(I can explain the soils better in the Chicago(land) region but have to type it all out
(it is in Flora of the Chicago Region a well laid out book a ten pounder)

Also do not forget to add references like persimmon Pudding
Unfortunately a lot of the Profiles for the tree’s are not filled out


I like your idea, and i was wondering lately why kaki isn’t grown more in the EU (never seen any tree’s in the Netherlands)

So this information would even be useful to people in other continents.

What specifically do you mean with “Wiki page” and “wiki links” ?
Do you mean a page on Wikipedia?

I hate to be the bearer of bad news. But personal experience is not really accepted on Wikipedia. Wikipedia is more science (source reference research etc) based than experience based.

I would like the topic here though. Or maybe in the reference section of this forum.

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The problem is that microclimates will wreak havoc to the best intended guesstimations. Heck you even have micro-micro climates (just made that up) where if you plant a tree in the field it will outright die but if you plant it next to the south facing wall of a heated building the combination of warmer soil and radiant heat will let it thrive.

I’m in zone 4 but in the winter time I can get several days of 40MPH at minus 10f (or lower if the gods are angry). In a hurry the definition of zone 4 becomes moot.

i don’t think micro climates will be a problem in this case. The degree days are full days X the temperature above X (in this case 70f). Measured from air temp. (like in the field, or near the tree)

If the degree days are enough to ripen something in the field, they are more than enough to ripen it near a wall.

The only exception would be if your planting at the bottom of a large hill in an wind sheltered area. But how many of us are? And is that even considered “micro climate” ?

your micro-micro climate has the same defenition as the normal micro climate?

A south facing wall is a certain micro climate.
How does that become “micro micro”?

Okay I see it explains it better comouter was about to die will look into later,
but I have brought this up before on the subject of degree days , and you even wrote about being in a maritime climate

Does this take into account the Humidity , and the ripening of fruit ?
When asked before I’ve been told a data base does not exist

I think your Idea is a very good one, well thought out, but do not over look that.
Also for Rootstock a option for Unknown would be good
also for grapes ground saturation all the time has the grapes ripen later I just remembered

There are three main types of degree days: heating degree days (HDD), cooling degree days (CDD), and growing degree days (GDD). I’ve focused most of this article on explaining heating degree days. Once you understand how heating degree days work, it will be very easy for you to understand the others.


Micro climates are traditionally understood to be larger than a south facing wall. A valley where cold air settles, bodies of water, urban areas, wind corridors, that sort of thing. A south facing wall is too small to be understood as a micro climate but very useful. Check this illustration:


I grow borderline grapes next to such a wall. Were I to plant them 10 feet from the wall they would probably die. The reflected sun also melts the snow earlier than on the rest of my yard which buys them the extra days they need to ripen fruit. I know of a person whose plums kept suffering from winter kill every year; you could tell what the snow depth was in winter by how much of the tree was dead. He moved next to his south facing wall and the winter kill stopped.

A Coincidence you brought up grapes I read a lot how the type of rock affects the grape
Yes I understand Persimmon tree’s are large,
but what about Urban heat islands temperatures being so much higher from the asphalt

Dark colored soils rock retain heat (lava is porous does not retain as much heat)
white reflect it , helps with reflecting light back towards fruit.,
(but persimmon trees are big so not sure if that helps unless low?)
would pruning the leaves so the fruit is exposed to sun help ripen them (like grapes)?

It has been a while since read up on the different (mineral’s color ) soils having a effect on grapes ripening not to get side tracked , but could have a effect on winter hardiness during winter at least. (but maybe even giving the tree’s a head start, and in some places a winter freeze I do not know all speculation ?)

Thanks to all for your thoughts, perhaps it may not be approved, but if there are enough interested people, we can still figure out a way to collect the same data from those who have successfully ripening persimmons. If wikilinks will not approve it then there are other ways we can invent!
Nevertheless, I will attempt to address several questions:

  1. I chose this particular website simply because it serves all 50 states. It was never intended to measure “growing degree days”, however, you can use it for that purpose. All it is is a calculator available to reference any of the know weather stations in the 50 states. I tried testing several other websites set up to measure growing degree days, but all I found online were restricted to regional cropping. We need one that covers the entire 50 states so that the experience of a grower in New England can be relatively compared to another location with a weather station nearby! I do not know what it generates for regular Dos based PC, but I wrote down the step by step process to use to generate the spreadsheet for an Apple Mac PC. See below process.
  2. The reason I chose Wikilinks was not my original idea, but was suggested by the Forum managers.
  3. I would like to keep the scope of data collected limited to only key information that relates to “Criteria that influence the ripening of Persimmons”

Again, give me your best input. If someone has a dos based pc, perhaps you can write out the steps to obtain a similar spread sheet.
Degree days calculation process
Step by step process for an Apple computer

  1. Set calculator to same settings as the pic below

  2. Click on Generate Degree days (you should see at top of screen a message that says “ Your degree days are ready (Download now))

  3. Click on Download icon

  4. In the right upper corner of your computer screen you will see the Down printing arrow, click on the arrow, then double click the file and it should come open as an excell spreadsheet.

If your Mac is up to date in its operating system you should get the spreadsheet. Like the one just below.


Sorry, here is what your spreadsheet should look like after generated and uploaded

When I post you have to realize that I’m coming from my perspective in Alaska. I figure some of the tricks we have to rely in here can be useful elsewhere.

Urban heat islands can go beyond just asphalt. Take the city of anchorage, which by itself the whole place can be considered a microclimate. In Bootleggers Cove and southeast into down and for a couple of miles can be 25º F warmer in winter than the coldest neighborhoods around Bicentennial Park. But in summer, Bicentennial Park can be 10º F warmer on clear days. A few miles can make a huge difference as to what will grow and thrive in both winter and summer.

Soil color: I think that for the most part what you can do is accelerate the warming of the soil and the color has a huge effect on how much solar energy it soaks up. My issue here is that the same snow that keeps the soil from being exposed to the worst air temperatures also keeps the soil from warming up as it reflects and stops the sunlight from reaching the soil.

I keep a pile of compost next to that same south facing wall. In spring time I will take shovelfuls and spread it on the snow; the dark compost warms up in the sun which melts the snow which allows the sun to heat up the soil. I can gain an extra week with that, and when your number of days between first and last frost can be from 105 days (90% chance) to 142 days (10% chance) every bit helps. Heck just shoveling the snow from around your trees will help warm the soil faster.

A trick I leanred my accident is spreading grey wood ash It melts snow
(it was half a foot or a foot deep)
I saw your in AK before writing .

Keep growing out the seeds to build up Generations of hardiness
I saw people getting pollen in a year by keeping them potted from persimmon (& passiflora incarnata ) forcing the plant for survival , maybe breed lines very fast to adapt …

(we have 100 year old persimmon that bear fruit that ripen at Morton Arboretum
( we get -20 F (-28C) and got polar blasts of -40 before.

Do you vint wine with those grapes you should try growing Rhubarb (ABV 9%)
which is a flavorful Dry white
(not subtle like cheap store bought wine,
but in that style you buy from the store just good quality though )

**Dennis D I will try with that suggestion you emailed me **
**not very good with Computers **
If you’d like my area code is 60505
(the airport is the best one for me on Romeoville RD. but more in the farm area 20 mintues away)

You don’t even need to ‘breed’ plants through sexual reproduction. A lot of adaptation happens through epigenetic memory; the ability of plants to regulate DNA expression without altering the DNA itself. Plants can learn and remember their environment; the composition of the soil, water cycles, seasons, insect pressure; all this and more models how DNA is expressed on the plant. After several years the plant truly becomes adapted to its environment and this adaptation is retained when you clone plants through asexual reproduction.

The bulk of the plants that nurseries carry up here come from the lower 48. This is unavoidable; by June 1st some of my plants are just beginning to leaf out and they need to be able to sell fully bushed out plants; no nursery would survive the limited turnover rate of selling only plants grown here. The downside is that those plants with the potential to be hardy can still have a heart attack the very first winter and not even get to see the spring.

I have strong winds during the winter time. Another trick is to take a 30 or 55 plastic gallon, ideally white, take the lid off and cut it lengthwise. One half then be installed so it protects the plant from the worst of the wind while keeping it outdoors in the cold learning the light and temperature cycles.

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Thank you Don
I meant more for adapting to ripen
It is good to share since this is a forum,
I could of added about epigentics in passing , since I am not the best at explaing these things
but you explained it well .

I actually Just got done reading about it as well
(not a fan at all of all the BIOtech stuff here,
but good to know what is happening )

I do appriciate the explanation ,
but a new topic on it could be good as it is something that interests me
(I think I may have mutated a Avocado plant by growing conditions it took many years to do so, , but it died)
I know this even can happen to peop
like that woman that swam to Russia in cold waters her body grew a layer of fat during her Training )

I am in Z5 Omaha, Nebraska. Winter low can be down to -29 F (not happen too often) but average low probably around -12F. Average high for the summer is around 90 F degrees. My Prok ripened sometime at the end of August and mostly in the first week of September. H-118 is also ripen around the 2nd week of September also and the rest of the American persimmon varieties ripened in late October like Meader, MB#3 (Morris Burton), etc…

It will be ideal if you start the wiki page and post the link to it. Others can add their location data to it directly.

Yes that was the idea of Scott Smith and Alpea, but several have told me that approval is unlikely because it’s not “Notable “ enough! Has to have scientific proof somehow toget approved. But will try any way. I have no experience with publishing a Wikipage or getting one accepted for publishing, but thought some other forum members might give me some helpful tips. So far no one seems to have done it. Nevertheless I’m learning what data criteria most members say are critical to know in order to decide on a variety. If you know anyone familiar with Wikilinks I would like to get their advice.

The beauty of growing fruit is that we need to adapt our thinking to our environment. Once we start paying attention the limitations of the USDA zone chart soon become apparent. We get to see -20~-25f probably once or twice but when it happens and the wind is howling at 45mph, the temperature number quickly becomes irrelevant. Wind is a huge factor on the winter survival of many plants.

Then there is the damn January meltdown… When it happens we can have a week of temperatures in the 40’s followed by 0f the day after. Anything silly enough to lose hardiness dies, regardless of how mild the overall winter can be.

Plus anything that is not ripe by mid September is a gamble; it is not uncommon for night freezing temperatures to start around that time.