Sorry for the poor link, it was the first one I found. Thanks for the advice
on getting rid of them.
Mikael

but if I had the OP's problem I think I would try painting the
unwanted plants with a mixture of a Triclopyr-containing herbicide such as
Brush-B-Gon and an adjuvant such as lamp oil. It works wonders on all
sorts of
difficult plants, including even Chinese Tallow Tree (Sapium sebiferum).