As is happening all over the country I believe, our plum tree this year
has hundreds and hundreds of budding plums on it: last year it bore 4
(four).

My wife has heard that we should really thin out the plums, so that we
get bigger, juicier ones --- is this correct, or is it merely a tale
without foundation?

If it is correct, what is the best way of doing it? Thin a bunch of six
down to 3, or 2? (By snipping off with a pair of scissors?)

Cheers
John