old plum trees

[greynomad]

I need some advice on some old plum trees:

Having worked overseas for a number of years, I'm back trying to get control of my garden again.

I've 3 plum trees, they are around 7-8 meters tall, they have not born any fruit since the 1980's, although are lush with green foilage.

I read August was the best time to prune, is it worth pruning well back:

Any suggestions as to what action should I take to get them to bare fruit again.

many thanks

[FB.]

If they haven't had fruit since the 1980's, then they might need a pollinator.

Do they still flower?
If yes; get a pollinator. If not; I'd remove the whole tree.

Could it be that a late frost is killing the flowers every spring?
If yes, then you still won't get fruit no matter what you do and I'd remove the whole tree.

Are you sure that they haven't gone into biennial bearing?
If yes, then you'll probably have to accept fruit every second year.


Due to their out-of-control size and lack of fruit, I'd try planting a pollination partner nearby and if the fruit yield doesn't pick up within a year or two, I'd cut down all the old trees and plant some new ones on semi-dwarf rootstock in a different part of the garden - and make sure that they get the annual attention that is required to maintain health, maintain crop yield and maintain a manageable size tree.

Badly neglected old trees can be more trouble than they're worth. At 7-8 metres tall, you're going to have trouble getting to the upper branches to prune them correctly. Simply snipping here-and-there will do more harm than good. Pruning probably needs to be "thinning" (removal of whole branches) and not "shearing" (i.e. not giving the tree a hedge-trim). You will not be able to transform them into good croppers in one or two seasons; it will take many years of intelligent pruning to get them back into production. Get the pruning wrong and they will turn into very untidy and ugly trees that still don't produce fruit.
I think that their sheer size makes it difficult to do much with them now. Pruning wounds after branch removal would be so large that they'd never heal properly and disease would set in.

But as I said, I'd see if a pollinator helps to get them fruiting again.