On April 18 (16 days ago), I bagged a dozen bare-root persimmon seedlings, bench-grafted them (all W&T), then attached them to a hot callus pipe. Temps in the callus pipe were generally ~85 F. The garage in which these grafts were stored has been ~50-60 F.
Roughly 7-10 days ago, I potted the trees but left them on the pipe. Today, I see the first signs of growth. Note that outside temps are still cool – 65 F days, 50 F nights; I would not attempt field grafts of persimmons here until at least late May. So the hot callus pipe has brought me success 6 weeks ahead of schedule.
Now I’m gonna move these to my basement (low 70’s) to grow under lights until outside temps get a little warmer.
These are the hybrids Chuchupaka and Dar Sofievki.
Don’t be distracted by the plastic bag and duct tape over the pot – That’s just a way to prevent the potting mix from falling out when I turn the pot on its side.
Finally, just a footnote: I have another 13 rootstock trees that I’m grafting with a different strategy. I potted them, stored them under lights in the basement, waited for them to leaf out, and then grafted them. These trees have been leafing out over the past week or so, so I’ve grafted as available. I think I will move these to the pipe until I see signs of growth from the scions.
Addendum 05/07/25: As of this morning, 5 of 12 grafts from the initial cohort attached to the hot callus pipe show growth – green buds / shoots popping through the tape. Those include 2 of 3 Chuchupaka, 1 of 3 Dar Sofievki, and 2 of 2 H-118.
Addendum 5/10/25. Now 8 of 12. Add a Taishu (1/1) as well as one more each of Chuchupaka (3/3) and Dar Sofievki (2/3). Waiting on 1 final DS and 3 Cardinals.
Addendum 5/24/25. Now 9 of 12 on the pipe, as one of the Cardinals is popping. What remains is 2 Cardinal and 1 Dar Sof. Also 6 of 11 on the other strategy, waiting for leaf-out. What remains is 3 Cardinals, 1 Taishu and 1 Dar Sof.
Final note 5/30/25: I’m wrapping up this exercise. The cohort sent to the pipe remains 9 for 12. The non-pipe strategy remains 6 for 11. By variety, it was 2 / 2 for H-118, 4 / 4 for Chuchupaka, 2 / 3 for Taishu, 6 / 8 for Dar Sof, and 1 / 6 for Cardinal.
I check the 5 failed Cardinal scions for continued viability by snipping off the tips. Four were bright green. I had damaged one of those grafts, which I tossed, but I left the remaining 3 grafts intact, hoping that one or more rallies in the coming month.