We are beating back our bamboo hedge (in Zone 7b, OK) that we inherited with our house. I've found about 3 feet will be ideal for enough fullness to shield the 2 story houses around but still give me a maximum lawn/non-bamboo area (our hedge is about 90 ft long, so we are bamboo-d out). Our grove had been neglected, so as we thin out the dead canes, we have some areas that are only about 1 ft deep and it's a little sparse. The 15 foot deep areas are being slowly and painstakingly dug out to make lawn available.

My understanding is bamboo roots will not damage a house's foundation unless there is already a crack in the foundation. Bamboo can invade a crack and begin undermining your concrete. As you know, the only thing concrete guys will warranty about concrete is that it WILL eventually crack.

I am a newbie, so take my info with a grain of salt. Hopefully someone more knowledgeable will be along soon. Definitely invest in a barrier if you grow a running bamboo - our seller did not, so we are trying to beat it back enough to install a barrier/sand trench to maintain it. It is super aggressive in our climate without a barrier.

Width of foliage is likely dependent on the variety - our golden bamboo has foliage spread of about 3-4 ft per culm, but seems thickest up higher, i.e. down at my 5' 4" vantage, it's pretty much straight up and down, but up around 10 ft starts bushing out with a triangular/umbrella shape, shaped kind of like a Pine tree.

Bamboo will not damage a foundation, whether it is cracked or not. Unlike tree roots, rhizomes (bamboo roots) do not increase in diameter as time goes on. A rhizome might go into a large crack in a foundation, but it will not try to get wider than the space over time, so it essentially poses no structural threat like other roots. Rhizomes will also not damage other things like fence posts or clothes line poles. And they do not threaten or invade underground pipes or sewers. The only physical damage I have ever seen done by rhizomes is when they go under asphalt. Because rhizomes seek out warmth, they can exert upward pressure on asphalt and cause it to distort in the summer when the asphalt gets hot and pliable and the rhizomes lengthen. If this happens, you will end up with a permanent hump in your asphalt, although it will not get worse over time as it would from a tree root.

Thank you both very much for your help!

jlc-
I am traveling right now, but will try to provide a little more info when I return tomorrow.

Spectabilis and virella, according to Brad at Needmore Bamboo in Indiana, are his two best phyllostachyses for cold. He gives them an A+ rating, so I assume they get no winter damage at all in his zone 6. He gives nuda an A-, so one would probably plant the new and exciting,parvifolia, which I grow, which gets an A or A-, known as the "moso of the north", before nuda for it's documented four inch culms in Holland. I don't think anyone plants nuda anymore, as the go-to boo for yanks, the consensus nowadays seems to be spectabilis, and that published ratings of nuda are inaccurate. Anyways, Brad's a very knowledgeable bamboo grower and grows over a hundred species. His website has an extremely helpful page on his observations over the years in regards to cold. Speaking from my own experience, three foot wide provides a dense visual screen with rubromarginata.

Presumably you are talking about Phyllostachys aureosulcata 'Spectabilis' and P. vivax. I think I've seen something to the effect that the problem with P. nuda may be one or more other, less hardy species being circulated under the name.

As with all plantings being done for architectural effects, the ability of the plants used to tolerate the coldest winters that come along later is critical.

P. virella (not P. vivax) and P. aureosulcata "spectabilis".