Keeping bamboo in pots for privacy screen
The only way bamboo will spread is by rhizomes. Which are pretty much like roots. So as long as it can’t travel from the plant through dirt in a path someplace else it will fine. Bamboo does not drop seeds. Well it does but only once every 50 – 100 years or so.
Yes you can get bamboo already tall. Or just grow it from a smaller one. You can buy 6 foot tall bamboo for a reasonable price online. Get’s pretty expensive if you go taller. In about 3 years it will have grown quite crazy even from a smaller pot of it. I bought some that were about 2 feet tall and very small and this year they are shooting at about 5 feet so far, and still growing. Some of my bamboo from the year before are looking at 10 feet maybe this year. Except zone 5 is another matter.
Zone 5 is brutal on bamboo. That is the limit for only the most cold hardy species. And even then it usually dies back every year to the ground and will regrow in spring. But that’s in the ground. In pots, probably forget about it. At some point it will probably totally die all the way in a pot. If you could wheel the pots in some place for the winter you’d be fine. Doesn’t have to be in the house, just some place where winter isn’t giving it a beating and slightly warmer than outside. Maybe a shed with a roof that lets light in or something. Probably won’t even die back at all then. And will look nice all year.
So if you can do that Phyllostachys Bissetii is very dense and very cold hardy. There is a dwarf version that is a little smaller also. That might be even better. I just started growing some myself. But again eventually so many roots and rhizomes will grow that you’ll have to thin it out in a pot so it doesn’t get rootbound. Good news is you can always sell those divisions you take off it. Or use them in other spots of the yard.
Or if you can somehow manage to find a place in the ground you can just use a bamboo barrier (thick plastic barrier, you can buy online). The bamboo will take a beating in winter and die back to the ground but pop up from the ground in spring. You can throw a tarp over it to help it survive better too and protect it through winter. We have plenty of collectors on the forums that grow bamboo in New York, but it does take extra work, and time.