Richard,
I hear you saying that you need mature scionwood to get pear fruit
earlier. Not so here! A few years ago, I took scionwood from my six pear
varieties and grafted them onto a neighbor's Parker Pear. Starting the
following year and for every year thereafter, he's been enjoying a bountiful
harvest while my trees just sit there wondering if they ever want to bear.
I'm jealous.
BTW, regarding dividing zones into 'a' and 'b' climate zones, I was
under the impression that 'a' is adjacent to the next warmer , numbered,
zone and 'b' is adjacent to the next colder, numbered, zone. You have it
the other way around: "Mine are in zone 4a/3b (tending toward
the former)." Now I'm confused; which is it?
I plan to do a bit more branch-grafting to see whether I can
get something else to produce quickly. I suppose having a mature scion is
part of the trick.