Baz wrote:
Don't jknow about Jake's, but ours (2 years old, I think) is not at all
happy, with crinkley folded leaves and no fruit. :-(
Crinkly folded leaves. Could that be black or greenfly?

I think it probably is, yes.

My 2 cherry trees are riddled with blackfly at the tips on new growth.

Ours were last year, not so bad this year. Obv. all headed for the plum
instead.