Big Bluestem can tolerate some xeriscape conditions, but Little Bluestem is just a bit more drought-tolerant and can tolerate worse soils, IMHO. I've got Little Bluestem in various parts of my mostly caliche and limestone property, but the only place I remember Big Bluestem growing is a few near the ditch by the road, so I assume it needs a a bit better soil and a little more water. Then last year I planted one Big Bluestem up on the slope where I'm restoring an area that was bulldozed. It doesn't seem to be doing as well as the Little Bluestems in the same area.
