I doubt anyone can ID trees that closely related by leaves, bark or growth habits. If you’ve already determined there’s a slight difference in leaf color, that’s a good indicator they’re not both Santa Rosa’s. If they bloomed and set fruit – you’ll soon know.

I can relate to your anxious anticipation, those are two great Asian plums and Satsuma is my favorite early Asian. Those plumbs are easy to graft and it’s fun to buy a ‘base tree’ of one variety and graft on 2 or 3 limbs of another, leaving a base limb or two for pollination.

So, if you get fruit, you’ll know. If they’re the same … and you’re from around here - attend our grafting class/es next spring, gather wood from several other varieties (such as Shiro) at our “Scion Exchange” (Fruit Propagation Fair) - and put on whatever you want.

I wouldn’t be too concerned with the varietal name, if the fruit’s good, that’s what counts. If it lacks pollination, that could be a problem, you’d then need to know what you’ve got in order to ‘not’ graft or purchase the same as a pollinator.

Asian plum trees need annual pruning. That said, you can keep them to whatever height you’d like. We’ve had many a pruning discussion on this forum but from years of personal experience, ‘You’ are the determining factor to the height of a tree. You may bonsai them, or allow them to sprawl. The ‘dwarfing’ effect of rootstock slows them down but ultimately you set the limits. Each year it will go for it – and each Spring you limit its expansion.

You may prune them back each year to 3 buds beyond where that limb-shoot started, or 15 buds. The more you leave, the longer and lankier your tree will be. I’d say with annual pruning your tree will be from 8 to 10 feet high and about equally wide. Mine is! They need heavy pruning, so don’t be afraid to take them on. But with its first year in, I’d be pruning for structure, leaving the best formed limbs and removing only weak or competing ‘water sprouts,’ and little more. You’ve plenty of time.