Burgundy and Beauty are in sync with the Flavor Grenade growing in my yard. Santa Rosa blooms a little too late for me, strangely enough. Speaking of which, I've had problems finding a good pollinator for Splash and Emerald Drop -- so far, just Inca barely works.

Matt, In the link below have Q&A about apricot pollination. Tony Here is a link that might be useful: Hortiscope

Matt - I did ind out a few more things but it just seems to make it ore complicated. It turns out that toka is a hybrid between P simonii. P simonii is considered " an upright variation of P salicina. On top of that all large japanese plums used in california (most of the ones used for the hybrids) are actually crossed with simonii anyways. The difference I found (and im still not 100% clear on it) is that toka is more or less a P simonii/salicina x american plum, which as you noted seems to make pollination way less clear. The main problem with P simonii is "a severe lack of pollen" which would explain why the hybrids have a hard time pollinating eachother. From the little that I can understand it seems that the hybrids arent incompatible, its just little pollen to pollinate with. I guess Toka may have more pollen which is why its recommended as a pollinator. Plum - the U of sask article states grafting the P nigra scion low so that it will help initiate proper flowering. Charlie - that is pretty much what I have seen as well. Pretty much the reason why I posted. It does seem to go a lot deeper then that when it comes to toka. All those california plums are apparently salicina x simonii, and simonii is said to just be an upright form of salicina.....

I have a satsuma too, it is young. I plan to graft a couple other cultivars unto it. I also have 4 pluots, and a weeping Santa Rosa, so the grafting is more for variety than for pollination, but it certainly can help.