We used to offer more dwarfing
rootstocks such as Bud. 9 and M7, but now we will exclusively graft
M111 rootstocks on our
benchgrafts.
We've found that a warm climate has a dwarfing
effect on apple trees and M111 can be easily kept small enough to
espalier or pick from without a ladder. The smaller rootstocks like Bud.
9 also seem to be too wussy for our climate, easily
killed by borers and not recovering from damage very quickly. An
irrigation failure can also mean certain death for them.
On the other hand, more vigorous rootstocks like M111
and above are well-anchored and need no staking. They grow quickly
and recover well from damage. If you forget to water a week they
will take it in stride. They may bear fruit about the same time
you allow your smaller rootstocks to start fruiting. Seedling and
M111 rootstocks are
long-lived; 100 years or more is quite common. And with summer
pruning, you can keep them any size, even the same size as the most
dwarfing rootstocks.
Apple rootstock research is geared
toward cold climates. We have started the import quarantine
process for Hashabi apple rootstocks from Israel that have proven
there to be more productive in a hot climate. They should be
available in 2014 (sorry, nothing happens fast in the apple world).
