I have a number of apple cultivars on the same rootstocks for the same research. This year I’m just focusing on crabs. This will likely be the last year I request scions because I’m about out of room (unless I turn some more areas into orchards anyway). The “research” I’m doing is far from formal. I just want to know what will survive here and whether rootstocks influence that survival (or not).
Crabs are generally more reliable in long term hardiness here, but there are plenty of regular apples around too. I’ve got several wild apples (fruit larger than 2") here that are at least 15 years old, so they’ve seen some pretty wicked winters.