Grafting Sweet Bay Magnolia HELP

Hey folks,

I am not very knowledgeable on magnolia trees but I have noticed there seem to be 2 types of sweetbay magnolias. Deciduous and evergreen. Both grow in my area. I wanted an evergreen one and ended up with a deciduous. Now I am considering top working it to the evergreen type. I know magnolias should be grafted when they are budding. But any help or info on this topic would be very appreciated!

There’s a simi-evergreen one I’ve planted 20 or so years ago…generally single trunked.
But, my old brain can’t think of it’s cultivar name.

I assume if you’re going to McMinnville TN you can find some trees of some ‘evergreen’ ones.
(I doubt seriously any kept leaves at -19 F in recent years…but some do retain leaves colder than others.)
Should be 3 or 4 patented or trademarked varieties at least.
Don’t have time to go deeper into it at the moment.

I’m out of my depth on Magnolias, Populars and Dogwoods. We found a pretty wild Southern Magnolia sapling today. That is the wife’s thing. I did figure out the plant that stops me in my track with it’s scent is Not Sweet Bay, it is Loblolly Bay and is a Tea family member. Getting smacked by the spouse tends to learn you that way.