K wrote:
echinosum writes
But Bramleys are not in that "most of the time" bit. Bramleys need to
be cross-pollinated by TWO different apple trees. So you need at
least
two other different apple trees in flower in the vicinity at the
same
time to get your Bramley to fruit.

Are you absolutely sure of this? I've just gone back to 3 of my
references and they all agree that the second tree is to pollinate the
pollinator, that the Bramley only needs one to pollinate it. But my
knowledge of genetics is too rusty to argue one way or the other.
I purchased a number of apple trees, (not Bramley) taking advice from
the supplier and making sure that I had at least pairs of groups. Now
nature, being as she is, does not always follow the pattern, so there
are times when the trees in the same group do not flower together.
Another point is that unless you are a long way from other gardens there
will almost certainly be other trees near by. Added to that "crab"
apples, which are grown for decoration, are good for cross pollination.