K wrote:
I wonder to what extent fireblight is a problem with apples in the UK. I
ask since hawthorn is one of our most widely used hedging plants,
including in the fruit growing areas of Kent and Worcestershire.

Hence my previous questions about wind direction, rain, basically the
general position of the apple trees. However, in my case, one of my
hawthorns's branches almost touches the top of the apple tree ...

I'm still looking into it - takes a life time to know everything me
think ;o) I've decided also, with the help of a couple of friends, one
a tree surgeon, to move the apple tree to the lotty. We're falling an
elder which has outgrown it's position - self seeded there too we
suspect. It cast a huge shadow over a couple of plots - the apple tree
will go there. I'm glad of the outcome.