Bob Hobden writes

"David in Normandy" wrote
Would I be correct in saying the key thing for pollination
of a bramley apple tree is that there is another (different
variety) apple tree in flower nearby at the same time?

My books made apple tree pollination sound very complex
with lists of what will pollinate what and whether is is in
group one, two or three, but a web site I've just visited
implied that it simply comes down to having apple trees
that flower at the same time - is this the case?

I thought you needed two pollinators for Bramley.

No, just the one. But Bramley won't reciprocate so you need the second
tree to pollinate the pollinator.
--
Kay