[Celery]

Has anybody any idea what time of year you prune one.
                                                                                  Celery

[Yorkie]

You prune stone fruits e.g. plum in summer to avoid the risk of disease.  My hunch is that it's a bit late now this year, but if absolutely essential you might get away with it.

[solway cropper]

It's usually done in July but, as Yorkie says, you might get away with it. If you do try it I'd be inclined to cover the wounds with grease or something to keep out the air.

[peterjf]

prune plum trees in june / july , prune all inward growing branches , make the tree like a goblet

[evie2]

that answers my question about pruning plumbs Peter