Just yesterday I was looking up information that crossed that subject, but because it wasn't what I was looking for I didn't pay close enough attention. But my subject line was "apricot rootstocks" on Google. I seem to remember reading that there were delayed compatibility issues with tomentosa under sweet cherry, but I am not sure. I probably would try it myself just to find out. I have an Italian prune grafted to tomentosa and it is doing well in its third year, but is very, very dwarfed. It remains to be seen how long it will hold up. Good luck, Mark

Let's see what you have to work with when the root throws off suckers this spring. If they are small you'll need to wait until they build some girth and strength; otherwise it's just so easy to cut right through them. The first thing I learned to do was cleft grafting, and it's still a go-to for me. It works for a broad range of scion-rootstock size discrepancies. I mean you can have a scion matched with a rootstock the same size or many times larger. But if the sizes of the two are close do a whip or whip and tongue if you like. And I really like the way those meld. Sometimes I fall back on a chip. You can place a chip from a pencil-sized budstick on a stick the size of your thumb without much trouble, and you can do it whether the bark is slipping or not, and regardless of whether the wood is supple and splitting readily. Bark grafting is very, very doable, but I've had a few instances where the branch didn't seem to want to grow over the splice well, and the connection seems a little tenuous. But I have a link to a very good tutorial that will get you going on it. Konrad does a super tidy and precise graft that he has pictures of, too. I don't have the link at hand but he'll provide it, I'm sure, if you ask. Those are all spring grafts. In late summer/early fall you can do chipping and budding. These are designed to heal over in the current year and then emerge the following season. So I don't have an exact answer to your question. I do, however, have a caveat, and that is that I don't know as much about what I'm talking about as it sounds like. There are a number of others who frequent this site who do more, and better, grafting in a few hours time than I've done in my entire life. I'm closer to being a newbie than they are, though, so maybe my experience at learning all these things is worth sharing. Some of the things I try to explain are the ones that I've stumbled over while learning. Good luck! Here is a link that might be useful: Joe Real bark grafting link

Magnolias are often planted with the soil line at or just above the graft line. People then add soil over a period of a couple of years until the graft union is completely buried. They do it this way to make sure they don't immediately suffocate the rootstock(allowing the rootstock to adjust to the higher and higher soil line until the top graft is well rooted itself) before enough of a root system has grown from the top graft to support the top growth. This is done by some people with some fruit trees as well. Many people prefer their Magnolias on their own roots for various reasons. Many have found that in fact many Magnolias grow much better on their own roots than grafted. Some do it because they are zone pushing and if the Magnolia dies back to the ground and is on its own roots, when it grows back it will be the same Magnolia they bought and not the rootstock. If done correctly, it can be done with many(most) grafted trees. Though, if you plant the tree with the graft union well buried in most cases you will kill the rootstock before the top graft can grow any or enough roots to support the top growth and you will end up killing the tree.

i do it all the time; I usually cut a collar at or below the graft to satisfy the classification of the maple.