[NAFEX] Exploring the limits of kaki persimmon cold-hardiness (long)
Jwlehman at aol.com
Jwlehman at aol.com
Sun Nov 27 15:47:09 EST 2005
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
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.
PS. The Great Wall kaki flowers were hand pollinated to D. virginiana. All
fruits were seedless. Bummer!
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