I've cross-posted this from the Trees Forum, but am desperate for any advice from those with experience with the problem...

I live on a remote 100 acre bush block in Australia, and after returning recently from 5 years overseas, these monsters have taken over. Maybe an acre all told. The local council inspected the place in my absence, and is threatening huge fines if I don't remedy the problem. I'm aware of the 41% glyphosate cut and wipe process, and have used it with great success on a 100 metre perimeter of my house.

But the biggest area has a couple of thousand of these growing, ranging in size from 3 metres high to the rest (majority) around knee high and lower.

My question is this...since the roots are all interconnected and glyphosate is a systemic herbicide (travels through the roots), would it work if I treated just the larger and medium sized trees and let the glyphosate travel to the smaller plants?

It'd save me weeks of work and give my creaky knees a rest!