"Eigenvector" wrote in message
The other suggestion he made was a big tarp - not a bad idea as it would
starve them out for light but you could cut holes in the tarp to avoid
killing the plants you want to keep.

How do you propose getting rid of the contaminated tarp afterwards? The
bottom will be coated with the oils.

I vote for Roundup. It has worked well for me, but it was minimal compared
to what you have..