Multiple trees, single planting hole -- yeas and nays?
I have six southern apple selections on M-111 in 10-gallon pots and have only a moderate amount of room to try them in (three more will be available in a year or so). I can graft to a more-dwarfing rootstock but that makes a considerable delay for my trials and M-111 has some advantages for my infertile and droughty deep sands. I can also multigraft one tree but multiple trunks may be easier to maintain as codominant growth. Realizing that diversity rather than abundance of production is my goal, is multiple planting at least OK? Is there any serious disadvantage to this odd planting practice?