How do I kill a briar rose stump?

[ErrolTheDragon]

I've got a briar rose stump, the rootstock of a standard that it outcompeted long ago. I made the mistake of not dealing with it ASAP as briar roses are so lovely for their brief season, but it's in the wrong place and really needs to go. But the root is now quite chunky and it's right next to a fence, with Ivy roots in amongst its own I'm sure, so I very much doubt it can be dug out. So, how do I kill it to stop it sprouting again? Will just continually cutting off all new growth eventually do it or is there some other way? There's a bumble bee nest in an old bird box a little way along the fence so Indefinitely don't want to use anything that could harm them.

Could you get beneath the soil and use a pruning saw to get through the roots much lower down?

Maybe, though it's in a restricted location because of the fence. I did manage to get a dead rhododendron root out elsewhere after using loppers on various roots , but the fact it had been dead a year did help.

Keeping cutting any new shoots will eventually kill it. It needs green growth to make energy, the stores in the roots won’t last forever.

Ruthless pruning of the new shoots - it may take a while, bit if you attend to it frequently the shoots wont have the hard vicious thorns... and make sure it isn't sneakily popping up the other side of the fence !

The neighbours' drive is the other side of the fence, a foot or so higher so I don't think it will grow out that way.

Right, that's all trace of green lopped off. I'll try to have more of an excavate this weekend and see if I can sever some roots - I don't mind if I get ivy roots too, that's too rampant anyway.

I'm going to be sticking some annuals in this bed for now and then we're going to widen and improve it and replant in autumn, so I'll try to at least weaken it before then.