Burdock

So what do I use to kill the burdock?

Brute force. dig it out.

Burdock does seem to resist the normal Roundup attack. I suspect the tap root helps it overcome the attack. Repeated cutting might work but if you only have a few or less it is better to just dig it out. Sometimes I cut off the big leaves and use them as a temporary mulch around some plants.

Weedhound.

jpw ~ full of one word answers