We have this bamboo growing tall and wide in the garden. Just what can one do to ensure that also the roots are stifled? ( - apart from pouring acid over it)
In the past I have cut it down, almost to ground level, then applied Rosate 36 .. but any of the Glyphosate based killers may do the trick.
Cant really give you instructions other than follow the manufacturers instructions.
Find someone who wants one and get them to come and dig it out - not that difficult unless it's truly enormous.....they can be easily split with the spade for easy transport etc. Which doesn't do them any harm.
Nb. they are quite expensive.
Apart from resorting to agent orange, the only way really is to blitz it by digging out the roots with a stout fork or mattock.
Once cut down to about a foot, you'll start to see a chink of light at the end of the tunnel and then you can digging and chopping away at the clumps of roots.
With that job done, keep a keen eye out for any new sprouts that you may have missed and remove as and when you spot them.