I tree loaded with apples like that is at best an invitation to biennial bearing and is likely to cause runting out. Don't really think you want a tree as small as M27.

I've grown a lot of M9 size trees with good results. Many people on here say M9 is too dwarfing. But that would be my recommendation along with one size bigger, M26.

You might want to look at the Geneva rootstocks in that size range.

Thanks Fruitnut...

I agree with Fruitnut- both about the need for thinning and that a slightly larger size would work better.

B9 (similar to M9, but hardier and more fireblight resistance) seems about perfect sized to me. In theory, I like mini-dwarfs and I have quite a few, but I haven't seen much production out of them. B9 is able to grow quickly enough to get 6-7' tall by the second (3rd at latest) year, at which point it can spend it's energy in making apples. M27 may flower its second year, but it will be too small to make more than 1-2 apples at most (at least for the 6-7 M27's I've planted).

I'm not saying that you'll never need to prune, but I've had very little on my B9's, as of their 4th leaf. Trees on G11 and G16 have been getting a bit on the vigorous side for me and I've had to both prune and tie down a lot of branches.

If you want something a bit smaller than B9, but bigger than M27, then G65 is a good option. But, you won't find many varieties on it and will need to graft your own. Cummins sells the rootstock.

That photo must have come from a catalog. Wouldn't surprise me if that photo was shopped.

Depending on how much land you have, I agree with Fruitnut. A semi-dwarf tree will stand on its own and is not a water hog, especially when mature. You can start to get all of the benefits of nature when you can include them. Otherwise, you have to do their work.
John s
PDX OR

Semi-dwarf will get larger than I like to deal with. B9/M9 is considered fully dwarfing. Even G11/G16, which are considered dwarf, not semi-dwarf, get pretty large. M7 and G30 are examples of semi-dwarf rootstocks. Of course, one benefit of SD is that you may not need to stake them, based on the rootstock.

It depends on how much rain you get, but I rarely need to water my trees. They have a thick layer of wood-chips as mulch, which helps get them through most dry spells.

Thanks everyone...the picture is just a reference for size. I have 5 other apple trees on semi dwarf root stock but I was looking at the future and I know I'm not climbing a ladder in 5 years to trim them anymore. I'm not looking for volume of apples either, been getting to many now but love the option to grow different verities and enjoy them off the tree.

Bob z thanks for the added reference on root stock. These will be in a wet area of my yard so EMLA-27 says it can handle it. Will check out the others. I'm planning on staking and fencing for deer and rabbit being these look to be a little pricey and my yard is full of them....thanks again.

For wet areas G65 may be a bit better than M27 due to higher resistance to crown rot. This table gives a good comparison. B9 and G41 are other small rootstocks listed as "very" or "highly" resistant.