It's necessary to net it in such a way that the birds can't reach the fruit through the netting, or by pushing the netting towards the plums and reaching with their beaks. Very clever are our birds! Using a technique handed to me by grape growers, I use bird netting clipped together by the plastic bread bag clips. Works really well!
It's a lovely shaped tree and I love having it in the garden, fruit or not.
This year it produced abundantly for its size, and although the birds did get a share, and although the netting was swirled out of place by gale force winds, I have just picked these plums which I am delighted with!
Thank you, plum tree!