I wonder if anyone has knowledgable advice. I live in Oakland, CA. I bought 3 apple trees this weekend. A pink lady on m7 rootstock, a anna apple on m7 rootstock, and a granny smith on m111. I wanted to plant all three in same hole in our small front yard. I am committed to pruning to keep size down.

I have 3 questions:

1) Can I plant these in same hole with different rootstocks?

2)The nursery said I can litterally plant them inches apart in same hole as long as I prue internally growing branches off-is this true?

3) How big will the roots grow and will they damage the cement border of the 8 x 10 garden bed?

Thank you