I believe St. Lawrence Nursery uses Americana stock on all their plums including the Europeans.

The plum graft compatibility is a maze, I have never found reliable data. Part of the problem is the non-Europeans are usually crosses of multiple plum species. This spring for example I had problems grafting "Sprite" (a complex cross) onto a Japanese plum, but it took fine on Krymsk 2. Fortunately nearly all combinations seem to work for me, including ones which I was told would not work.

Scott

FWIW, I seem to have been successful, at least for now, grafting a prune plum of uncertain heritage to prunus tomentosa (nanking cherry). It's about a year old and emerging from dormancy after putting on about 12" growth last year. Each of three grafts to the same rootstock took and all but the main one were removed. I did whip & tongue and chip grafts.

Good luck.

M

Oughta work fine.
I've even put Euro plums on native Chickasaw(P.angustifolia) plum - not a good idea, since the understock suckers like nobody's business - but it was all I had to work with at the time.

Thanks for the input. I have lots and lots of Prunus americana to graft onto...