Wanted to throw in what i've learned about persimmon grafting to get better takes.
1) Graft in warm/hot weather with an actively growing rootstock. Temps are best when they are consistently in the mid/upper 70's.
- scion should be dormant, and 2 or three nodes long.
- wrap in parafilm
2) Use a bark graft technique with much more than the usual amount of inward pressure
- Scion should be trimmed to have a LONG contact point under the slipped bark.
- Inward pressure should be maintained: I typically use hose clamps of all things.
Until I was taught those things, I was frustrated with these trees. After, it isn't very difficult to graft at all.