I know of a local grove of large bamboo - not sure of the type. They
contain it by mowing only. I was under the impression that it would
still run and eventually reach areas that were not mowed or just keep
spreading underground despite the mowing. Is this correct or not?

Mowing should be able to contain the bamboo if the mowing is done regularly and
the area mowed is wider than the width the bamboo can spread in a year. A long
section of rhizome that has no culms will wither and die eventually, even if it
is attached to the mother plant. This is because without photosynthesis it
will not be storing any energy.

Regards,

Bob

Bob Johannnessen