Two of my dwarf apples were badly damages by rodents over the winter. I believe that they are on M27. One has responded to TLC and looks good, but the other top has clearly died. However, the rootstock has survived and is putting out growth. The growth is definitely from below the graft knob. BTW, just what is the rootstock -- is it an apple species, or something else in the malus family?

I would like to make use of this rootstock, since it is alive and growing, but I don't know what to do next. I have a standard yellow transparent that I thought I would like to try to graft to it. If I understand correctly, it is too late now to try to graft, isn't it? Or is there a grafting technique that is fine to try now or later in the summer? How best to nurture the rootstock until I can try a graft?

Oh, I will piggyback another question if you don't mind. I have two otherwise healthy thornless hawthorns that I am taking down because they are plagued with cedar-quince rust. Are their roots usable in any way as a rootstock for something? Will the susceptibility to the rust transfer to any grafted fruit, if they are?

I appreciate your help, thanks!