|Seeds of a Claypoole persimmon "I-115". Nominally pollinated by a persimmon named "Szukis"
Persimmons are surprisingly winter hardy and the fruit can ripen off the tree. One reason that they haven't migrated farther north on their own is that the seeds want a lot of heat before they germinate. They get a late start in the spring and are over-topped by competitors.
Cleaning persimmon seeds for shipment is tedious. Each seed is encased in a sack of slimy membrane.
To date, the best method I found for cleaning them is to squish the persimmons. The riper the persimmons the better. Flood the goop. Drain off as much pulp as possible.
Repeat several times.
Spread seeds on newspaper. Rub the seeds into the paper. Replace paper when it is soaked or so lubricated that the seeds skate across the top.
Eventually the slimy seeds will be dry enough that they will "grip" the paper and the membrane will tear as you rub them across the paper.