I would agree with not using any systemics on any edible fruits/plants (Many of them are now being tied to honeybee colony collapse too. The bees IMO are just the canary in the coal mine). For most trees you need nothing to seal a pruning wound, the tree will take care of it. This assumes that healthy wood was removed, and done properly so that the growth area at the base of the limb was left intact. Look online for some diagrams of how to do this. If you must use something, the old black oil based tree wound compounds are still available. As for borers, there are quite a few options for killing them once they are in a tree, from running a wire up their hole, to injecting predatory nematodes or insecticides in the hole. General prevention is harder. One source claims that white interior latex mixed with spackle (sheet rock joint compound) to s spreadable mix, painted on the base of the tree works. Others claim fine gravel at the base of the tree will deter borers. And their are traps for the adult borers too.

Hi Phil, From your post, lots of woody growth, lots of borers and then fungal attack, pruning may help,but you are prolonging the agony of the Lemon. The costs and time factor, saw and dig out the butt if possible, drench the area with a good fungicide, back fill. If posible replace with a new improved version but a few meters from the old one, to try to stop any soil born nasties transfering to the new specimen. We all like to hang on to old faithful things, but there comes a time to say goodbye.Good luck, Peter r

Hi Blackolive, Sorry to say your lillypilly sounds like it may become a widowmaker, without getting an ultrasound examination of the trunk and major branches, the tree will always have that unknown dangers of collape of the tree at any time. The parts of the tree that are dead or dying are left open to attack by white ants, borers, disease, rot etc,will be hanging there just waiting for an opportunity to fail and the tree to collapse at some un oppertune time in the future, possible with someone climing the tree or sitting near the tree and being injured by the tree falling. IF IN DOUBT CUT IT OUT ???? Please be saftey minded of yourself and others that may use the area around the tree. A ticking time bomb possibly. You can always get a new tree, but if it falls on some one or something, maybe abit harder to replace. Good luck Peter r

Rayrose, just wanted to say thank you for the advice, I think I may have dug out all the borers from my peach trees and added the Triazicide to the soil as well. Today I dug around the base a noticed there are new roots growing and I don't see anymore frass. I still see a bit of jelly like substance around some of the wounds, but I think that's probably a normal part of the healing process for a tree that went through damage. The new roots and no frass has me thinking I may have gotten rid of the borers, that and the trees look good and healthy. Thanks again Matthew