Has anyone here grown a mature ungrafted M7 apple tree?
Has anyone here let an M7 rootstock grow into a tree of its own with nothing grafted onto it?
I've let branches grow and produce fruit below the graft union, but for some reason I've never actually let one grow to more than a few years old before grafting a cultivar onto it. Right now, I have a little less than 500 3-yr old M7's waiting to be budded, and I'm seriously considering leaving about 90 ungrafted. The fruit is pretty good, similar to Macintosh, and they're about as juicy, too, so I figure they'll make good cider. If not, they'll make good fodder for the cows, goats, and chickens. I write this for the naysayers, who might say that the fruit would have no commercial value. Well, apple cider, milk, eggs, and pastured meat definitely aren't worthless.
Anyway, if someone has grown an ungrafted M7 to maturity, what is your experience with it?
Our M7's are spaced at 9x15 ft. Will an ungrafted M7 spread 9 ft wide, or will there be a lot of wasted space between trees?
Is M7 a regular bearer, or does it have strong biennial tendencies? I'm thinking the latter, since it is a type 2 semispur.
Thanks for any replies.