Japanese Plum - frost hardy - early ripening?

[TNHunter]

Stan’s harvest diary 2021

Opal plums, the first of European plums (along with July Green Gage) to ripen. Flavor is mild but very pleasant. [2021-06-13_Harvest_Plums_Opal_IMG_0837] Catherine Bunnell plums (a Luther Burbank selection, has been considered a lost variety for a while). A nice early Asian plum, flavor is a bit reminiscent of Santa Rosa, but the fruit size is smaller. [2021-06-15_Harvest_Plums_Catherine_Bunnell_IMG_0840] A Howard Miracle plum tree, I expect these plums to start ripening in a couple of wee…

A few details on Catherine Bunnell plum… from Stans harvest post.