Bamboo's have quite a fearsome reputation, for being invasive. Having seen some in North Carolina growing stems six inches thick and thirty feet high, that could be a regrettable plant by most ponds...
Some bamboo's are stunners, I grew a 'phyllostachys' for years in england, a gorgeous plant for a plant screen, it divided real easy every year for new positions, spread at a modest reliable rate, grew to ten foot tall with a thin stem...
A careful search of websites describing bamboo growing habits should turn up a real good shortlist of varieties good for most situations
Miscanthus is another good screening plant, reliably over six foot tall, a very attractive plant all year, as is bamboo. On a quiet night nothing can move among miscanthus, it's one of those 'whispering' plants which rustles in the slightest breeze, quite a spooky sound after dark which I'm fairly sure keeps creatures of a nervous disposition steering clear of it
As security plants, yes, bamboo's can be breached fairly easy, there's usually gaps of some sort... pampas grass with it's razor edged leaves would be more effective
Regards, andy
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