Rootstock for stepover crab apple

[Spazturtle]

Hi, I am looking at growing a Dolgo/Pink Glow (low vigour) crab apple as a 3.3m wide stepover in clay soil and later down the line an apple as a 3.3m wide stepover next to it making 7.3m wide fence (including a gap in the middle).
From reading several old threads on this forum I know that M9 and MM111 do well in heavy soil and I was wondering which would be better for my use?

The site I am planning on planting it in doesn't have the best sunlight either.

Really it comes down to two things, would M9 even be able to grow to be 3.3m wide when combined with a low vigour scion and would it be possible to keep MM111 in check or would it be too vigorous to be used as a stepover of this size?

I have seen people using MM106 as a rootstock for stepovers in places with lighter and more fertile soil with much more sunlight then my site and I believe that MM111 is only a bit more vigorous.

Thanks in advance.

[Guest]

I would go for something like M26 but I don't know how they are on clay. I have found an old thread that suggests MM106 do quite well on clay. https://www.growfruitandveg.co.uk/gr...ons_53765.html
I would not be brave enough to use MM111 for a step over

[Kirk]

There is a 116 but not a great deal of information, suspect it gets missed and people go for 26 or 106.
Personally I would go for M26 but I read it does not like damp soils and clay can be both damp and rock solid.

The OrangePippin site seems to say the dwarfing M27 for step overs.

[ameno]

My apple trees are M26 on clay, and seem to do well. It's not heavy clay, mind, and it never gets waterlogged.