Look up a recent thread named " MM111 rootstock and three trees in a hole" which was started on Jan 13.

It is on the next page of threads.

There is a good discussion on the subject.

Mike

I never fully understood the method to his madness....

That many trees in one hole almost seems to force you to use a crazy amount of fert. I have seen something like this done using one tree and one support tree, which tends to fertilize with nitrogen (for instance a peach with a russian olive which can be pollarded then used as mulch)

I guess I see DW method the same as grafting half a tree to a certain kind. At least there would be less of a problem with nutrients. There could also be a problem with roots. Some fruit trees do what ever they can to keep roots away from eachother. Some could just mass together and could strangle eachother out (survival of the fittest remember)