Until this year my Phyllostachys aurea has been very well behaved sending
new cane up in or very close to the existing clump.

This year however it seems to have gone crazy sending out ground level
runners in every direction under the mulch sheet and gravel to 1-2m in
every
direction!

all the references seem to say non-invasive or well behaved except an
American reference to being an aggressive spreader in hot climates.

anyone any experience?


No direct experience, but I did do a fair bit of research (i.e. surfing)
some time ago. The consensus seems to be that Phyllostachys species, and P.
aurea in particular, are actually runners rather than clumpers if they're
happy enough i.e. given sufficient sun/nutrients.