These are a mixed bag of cold hardy rootstocks, organically grown here, zone 2 or 3 and full vigor. They include antonovka, dolgo, ranetka most years. We will simply send the nicest of these comparable stocks. If you are looking for a particular stock, email us. All stocks impart the same degree of growth in your scion, so unless you are particular about knowing your rootstock for other reasons like research, they should fit the bill for all of the continental US.