We've got about 20 full sized clumps of himalayan blue (we think, free for the digging on craigslist). As well as Phyllostachys nigra (reg and ‘Henon’), Phyllostachys vivax, moso, Bambusa ventricosa "Buddha Belly" and phyllostachys heteroclada. We're planning to put it all in and see what does well.

Anyway, we want to keep these under control so they don't take over other parts of the yard or escape into the neighbors yard. We're planning to put the himalayan in a row about 3-4' from the property line/fence and don't expect to need a barrier for it. Immediately south of that we'll put taller and more open/spreading varieties. Our soil is very hard and rocky (large rock) and poor (~subsoil) so deep trenching is not particularly attractive. We could dig down a foot at most. I'm considering a barrier that goes into the ground 1' and above the ground 1'. I could make it simple concrete, or bamboo barrier backed up with concrete/timber. Then I could fill it with better soil and mulch. Would bamboo break through a 4" reinforced concrete wall such as that?

On the other hand, with our crappy soil and dry climate in the east bay hills, we may simply be able to limit the bamboo by fertility and water since it seems only native plants and annual winter weeds grow in areas I don't irrigate. That would certainly be easier, but I imagine they'd run together and I'm not sure what the neighbor is going to do on his side.

I know a lot of you guys grow many species, and hopefully some are in CA, what would you do?

Of the bamboos you listed above, I'd go with only the Buddha Belly, as it is a clumper, however, a closely related bamboo that would do much better is Bambusa oldhamii.

Oldhamii grows taller and very erect so it will not lean outward as compared to the BB which will lean outward but still be within your 40' range.

Kt