Plum tree pruning and maintenance

We have had no success with our plum tree at all - mostly bugs getting into all of the fruit making them inedible, although we did have a bit of an improvement this year by using a pheromone trap. However, as the fruit formed, the branches flopped further and further over (to a worrying degree) and I am thinking that part of the problem is that I haven't pruned it at all since planting it nearly five years ago.

I am assuming that around now is a good time to prune it, but really don't know? Also, someone suggested washing/spraying the trunk with something - I think neem oil but again I could be wrong - any and all advice gratefully accepted as always

 

@Fat Controller Plums should only be pruned immediately after the fruit has finished. Pruning late in the year can lead to it getting diseased. The biggest disease problem for them is Silver Leaf. Never prune after July unless it is one of the few late season plum trees.