North American Fruit Explorers mailing list at ibiblio

[Jwlehman@aol.com]

Hello Richard,

I've tried many kakis w/o success. Grafted six of Cliff England's most hardy ones here including his two most hardy Korean varieties. None survived past the second year.  About half were totally killed the first winter and the other half gave up trying to exist after the second winter. 

Davis Lavergne has sent three varieties that are supposedly hardy, one Great Wall, that came form the north of China and as I recall brought into the US by a fellow NAFEX member years ago. It has been written up more than once in Pomona as being winter hardy. It and two others were grafted on a tree 12 inches from the South side of our home where a pistachio has survived for about 7 years. This is in a well drained site, protected from the cold north winter winds. Six kaki grafts were made twice over about a 6 year span for a total of 12, and all eventually froze to death. Yes, Great Wall did manage to survive long enough to fruit two years. Then as I recall -15 took it.    

Even planted about 125 seeds of Saijo and 200 of Jiro I collected from Dr. K. Ryugo's UC Davis orchard. That was about 10 years. Except for one year all freeze to the ground every winter then come back. Of the original 250 kaki seedlings, there survived this past summer about 12. They have gradually over the years decided this area is too cold, I would submit. Was hoping that at least one of each sex would be hardy here and flower. 

I've read Greg Reighard's and Jerry Payne's, a paper on Sudden Death in kaki (KSD) persimmons, which discourages large scale commercial plantings, until more is known about this malady. I believe their work was done in Georgia or Tennessee. I agree with their assessment that kaki can't be reliably grown in areas that regularly drops colder than 10 above. 

That certainly has been my experience here. Have had almost no shepherd hooking here which is a KSD symptom and I believe the reason is shepherd hooking is caused by uneven damaged wood cells so the branch grows unevenly, causing the new growth to be uneven giving the shepherd hook growth. In the field they are damaged so bad there is no growth, hence no hooking except the one by the house which did. 

I know of one grower who has a tree in Cincinnati, OH that survives and produces.  He is in the Ohio River basin which moderates the winters slightly. I had a report of a kaki in Kansas that was producing fruit. I wrote to and obtained scions. Grafted and they lived as I recall two winters, then froze to death. They didn't know the variety.    
 
As I'm interested in hybridizing D. virginiana and D. kaki I have a burning desire to have kaki trees that produce pollen as well as fruit. Thus far all of my efforts have failed long term. 

I agree and it makes sense that a well drained area might support kaki during winter temps to maybe 0 degrees by reducing the moisture contend of the dormant wood. I'm in heavy clay but remember the tree along the South side of my house is sand and gravel back filled about 8 feet deep from when the house was built. Also a concrete driveway drains water away from the house only 4 feet away. Pistachio is basically a desert tree not hardy to 0 F, but this one 10 feet away survives. These kaki grafts in this winter protected well drained spot have performed best, but we almost every winter drop to -10 two to three nights and eventually they all died.  
 
It has been my experience and observation that -10 is deadly almost every time. 

Regarding nursery catalog claims of hardy kaki: I have no doubt their claims are valid and under the right conditions kaki will survive exteeeem temperatures. But not one of the claims are backed with a money back winter hardy guarantee in zone 5. I'm in 5b.  I've visited they lady twice just south of Memphis, TN, zone 6, who planted about 500 Jiro trees for a commercial orchard to witness her bout with KSD. Her shepherd hooking was more pronounced than mine. Less winter damage? 

In an attempt to eliminate the KSD virus theory I obtained Jiro wood from Dr. Ryugo who has never seen KSD in his Wolfskill planting. I personally grafted maybe 12 of them in the TN orchard. They too shepherd hooked and died. Those scions should have been clean. She is on heavy clay, but fairly well drained. Now is her problem caused by cold, or maybe micro nutrient surplus or deficient? She has sprayed with micro minerals with no help. With everything I've seen and observed I must agree with Reighard & Payne, unless one enjoys efforts in futility and maybe a more true NAFEX'er than myself, if one's winter temps regularly drop to 10 F and lower, forget commercial plantings of kaki. Even a loose definition of commercial being regularly obtaining fruit for one's table.  

Someday maybe, and hopefully so, my assessment will be proven incorrect and we will have kaki that survive and fruit down to -10. In the mean time if anyone has a kaki that they believe will survive -10 please send scion wood, I'll give it the Indiana acid test. 

The Russian hybrid Rosseyanka survives well and fruits almost every year here. Did survive -31 (a record low) a few years back. Some damage, but no where near fatal. The fruit is kaki like, delicious. Just cut off the fruit yesterday to bring in to complete ripening.  

Jerry Lehman      

PS. The Great Wall kaki flowers were hand pollinated to D. virginiana. All fruits were seedless. Bummer!