North American Fruit Explorers mailing list at ibiblio

[Alan Haigh <alandhaigh@gmail.com>]

I don't like the 4 in 1 trees at all, although I'm not overly concerned
about the ethics involved with distributors of the product- it seems to me
to be a relatively minor infraction in terms exploiting customer trust-
especially as far as the big boxes are concerned.  I think that some people
are genuinely happy with the product- at least for a time, until most
vigorous varieties or variety takes over the tree.  If the nursery that
produces the tree includes non-compatible varieties I would assume it to be
an ignorant mistake.

I prefer a 2 in 1 or 3 in 1 tree where less vigorous varieties are grafted
on subsequent tiers of a central leader- an idea I wrote about in Pomona
several years ago.  The trunk itself is divided into different varieties and
by using less vigorous ones as you go up, you create a tree easier to manage
than any single variety central leader tree.

If you want to graft individual scaffold branches it certainly is best to
use varieties on the same tier that have similar vigor, which is something
that doesn't happen much as far at the multiple variety trees I've seen sold
(besides in my own nursery).  Most of them are intended to be open center
trees, which is a fine shape for the home orchard, but made much more
difficult to manage if scaffolds grow with a wide range in vigor.  If you
buy one, at least try to orient most vigorous varieties towards north.

Dave Wilson Nursery's big trick is to encourage customers to plant up to 4
trees in a single planting hole and treat the four as a single tree by means
of lots of aggressive summer pruning- the close proximity of the trees is
also supposed to be dwarfing.  The method certainly has an enthusiastic
following, although I've never seen any researched based information on how
efficient a method it is and whether or not it cuts into brix levels of
fruit.  I've seen plenty of evidence that too much summer pruning can have
this affect on conventionally grown trees, however.

It's not something I'm ready to endorse in the humid regions, although it
would be nice to sell the extra trees.