I have talked to a gentleman here in town who has quite a bamboo collection, and he told me to use metal flashing as a barrier with it tilted slightly out. Anyone else have any experience using flashing for containment purposes?
Over time it will corrode and you won't have a barrier where you thought you did. I find it much easier to rhizome prune for a few minutes once a year, rather then dig 30"-36" deep ditches to install barrier...and hope it works indefinitely.
Oh! I had been interested in some of the running varieties but was worried about invasiveness and didn't want to have to dig that much for barrier installation. The periodic rhizome pruning sounds good. Also I think I've seen mention that runners are 'less' invasive in cold climates?
you may have seen that rhizomes run less in areas with cold winters, many people state that but i dispute it or at least it needs clarity. take europe for example, milder winters than me but significantly milder summers as well and the runners often act like clumpers there.
i think the idea must be that cold winter areas that see lots of top damage may not have the energy to recover and produce both culms and strong rhizome growth which has some truth to it but rhizomes do not grow in winter they grow in summer, the longer,hotter,and wetter the summers the greater the rhizome spread. i am in a cold winter zone 6 but look at the heat zone map, i'm in zone 7. we warm up very quickly in spring with most phyllostachys shooting by late April, we get regular rainfall and we have hot humid summers. i bet i see more rhizome growth than growers in the pnw due to their drier, milder summers, shooting season is all but done here and rhziomes will be waking up soon.
i think the cold weather slow spread theory needs clarified to include how fast your soil warms in the spring.
having said that, i think that folks are way too barrier dependant and worry too much, rhizome pruning still works here where it is not uncommon to have a rhizome grow 15 feet out in a summer. barriers will create a false sense of security, even the industry products can fail. if you are planting on a property line and can not patrol the neighbors yard to kick wayward shoots that your pruning did not prevent then a barrier is a good idea but be careful with homemade barrier materials!