I don't think it's a good choice for you. Vivax is notoriously thin-walled and can easily break in half when it gets snow-loading.

don't waste your time on that one, concentrate on the proven cold-hardy ones like yellow groove.

All my vivax varieties do tend to get top kill starting at around +6F or so, and will get top killed with sub zero so I don't think it will be worth your time. It gets down to around 0F here and the boos that can take a winter here are the aureosulcatas, parvifolia, bissetii, propinqua beijing, decora, dulcis, atrovaginata and fargesia rufa. Anything else seems to be too cold sensitive to do much around here.

Stevelau, how big have your vivax varieties gotten?

They've maxed out at around 2/3 inch, and after a top kill they come back pretty weak. The other problem is due to the weak culms, they cannot be tarped to the ground without snapping the culms which makes larger culms impossible to protect from the winter.

It's much easier to simply grow something hardier because vivax is nowhere close to -5F hardy. I'm in the same zone and area as you so conditions should be similar. Many of these boos with top hardiness can stay completely green over a zone 6a winter once they get well established which is usually when they get too big to bend over and tarped to the ground.

As you can tell from the blog, parvifolia has so far been by far the fastest running, and close to the fastest upsizing bamboo in my garden, and it also holds green pretty well over the winter.

Here is a link that might be useful: Some of my bamboo groves

Nice bamboo Steve! I've included a picture of my P. Nigra Henon, it's about 8 years old. You can see by the milk jug that it's getting a bit bigger, but sadly it's not 60 feet tall yet, lol! I'd say that we rarely get winter temps here lower than zero, but then I'd jinx myself, so I won't say it, ha ha!

{{gwi:421466}}

I guess that's pretty good for henon, but I have boos like parvifolia, atrovaginata, dulcis, & propinqua beijing which have gotten close to powerline height, breaking the 10ft mark after 2 years, atrovaginata which has broken 13ft, so I think those species are more appropiate for a cool climate. After 8 years and still being well under 20ft, that may be the extent of it's potential in zone 6 if it top kills each winter, but I really don't know.

I've seen a yellow groove culm at 27ft where I got my division from which is not even a completely mature grove yet since it is still gaining height from year to year. Even YG which is a medium sized bamboo can break the 30ft mark here. I have seen a well maintained green phyllostachys which looked like Vivax with a high branching pattern while driving which had to be in the 35-40ft range, spread of around 20ft, with culms close to the 3 inch mark, but I'm pretty positive it's one of the species I already have so I never bothered to go back there, find out who they were to try and ask for a dig. I don't have a large enough vehicle to move anything that size anyways. Anyways I think either parvifolia or atrovaginata must be the ones with potential to hit the 40ft mark in zone 6 after many years of growth.

Has anyone in zone 6 ever seen bamboos beyond the 30-40ft range or is that pretty much the maximum? If I saw a 70+ footer in zone 6, I would have no choice but go for a dig even if I had to rent a trailer.