I just came across your note and , Yes, I have winter sown apples just for fun and maybe as some rootstock. It works very well as I sowed 8 seeds last winter and now have 8 little apple trees about 2 feet tall. I'll probably graft to 6 of them and let the other 2 mature in an out of the way spot just to see what I get. I used milk jugs and a sterile potting mix and no fert until a few true leaves showed up ( weak MG ).

Thanks for the follow-up! I put some seeds out in 4 jugs last month... looking forward to see what comes of it.

Well, 4 seeds survived out of a whole bunch sown. Ranetka & Dolgo (Baccata didn't take root at all). The little guys are about 6 inches tall and were transplanted from the milk jugs to larger pots. Hoping they'll survive the (too-fast) upcoming winter.

Update: none of the little guys (in pots) survived. I'll probably try again this winter & transplant right into the ground from the jugs instead of into pots, see if that makes a difference.

I thought from what I read that seeding apples was a bad idea because you won't get a good representation of the parent plant from the seeds, which is why people usually "start" apple trees from grafted branches on a rootstock. I think there's a couple types of apples that are true and can be started from seed but most you'll get an unpredictable type of plant.