Sandy soil, or even store bought potting soil work great, but will need a bit more waterings. If in a pot or raised bed, it will also need more water than an inground plant.

Spacing depends on how fast you want the area to fill in with bamboo. P. nigra is one of the most aggressive or possibly 'the' most aggressive that I grow. The first year I planted mine in the ground from a one gallon pot, it sent up a shoot 15 feet away at the end of the Summer, however that's not to say that there were culms everywhere. That was the maximum distance from the mother plant that a culm popped up.

In a confined area, it will quickly spread and fill in the inside of the barrier area. The third growing season will typically be your first best 'grove' year, no matter how close you plant the boo.

This is from my experience. Someone else in your area with a similar zone rating my be able to help you more.

Good Luck.

Kt