It's an excellent idea in fact! I currently have a mix of nigra with aureosulcata aureocaulis; the black and gold accent each other nicely.. I took your bottom line measurements for the calculation .. 3x2m I'd space them at a minimum of 3 feet which would allow you about 3 plants spaced at 3 ft apart (1 meter). You could also plant two deep if you want seeing as how you have about 6+ feet of depth.. Just keep them spaced 3ft minimum.. That would allow you approx 6 plants total.. Here's a makeshift diagram: X = Plant

X -----3ft----- X -----3ft----- X
(3 feet between)
X -----3ft----- X -----3ft----- X

Keep in mind that you'll need a rhizome barrier (high density polyethylene) approx 30" deep if you want to keep them from running.

Thanks Michael!!!!

Sorry I didn't reply sooner. I will put in the barrier my neighbors wouldnt appreciate bamboo in their yard lol. What size plants should I buy? I see them available at a size of 50-70cm for like 20 bucks all the way up to 2 meter tall for 70 bucks? How fast will they grow?

Ashlie-
Bamboo don't "grow" in the conventional sense. When you see a pot of bamboo, the culms you are looking at will not grow any taller or fatter. Each year the plant puts up new culms that are bigger than the ones from last year, until they reach the limits of their species. When you plant a clump of potted bamboo, it will typically spend the first year or two putting most of its energy into the root system. Then, when it feels established, it will start putting up new culms. The reason you see price differences for different size plants of the same species is that the the bigger ones are more mature and will put up bigger culms in subsequent years than what you will get from a smaller pot. Each species has its own size limit, which you can find out by looking at the species information on a site like the one below.

Here is a link that might be useful: BambooWeb

Thanks Kudzu I knew that already. My choice in wording was poor which is what led you to believe otherwise.

Hey Ashlie,

It all depends on how quickly you want privacy. If you go with a running variety then you're looking at APPROXIMATELY 3-5 feet of growth per year.. 1-3 feet with a clumper. With approx 2 ft tall plants (50+ cm) you'd be looking at a good 3-5 years before you'd start to get some privacy (rough estimate IME).
I think your best bet would be to spend a little more money if more immediate privacy is a priority to you. Go with 3-5 gal size plants at the least, i.e 5-7ft+
Remember: 1st year sleep, 2nd year creep and 3rd year leap in terms of spread.. So for the first year you're not going to get much more privacy than the locations where they'll be planted.. Hope this helps =)

Thanks Michael. That's what I was interested in hearing. I have a fence behind them so They really are more for decoration then privacy. I'm impatient though lol so I'll buy bigger ones.