What is this blueish-green grass about 3-4 feet tall that is growing now in dry, sandy soil?
this is most likely Andropogon ternarius, the split-beard bluestem. It is quite similar to Andropogon virginicus, broom sedge, but it does not have as many flower clusters and stems per clump. Most if not all of the bluestems have this blueish appearance, including little bluestem, Schizachyrium scoparium, and big bluestem, Andropogon gerardi, which is much taller.
Dr. Steven Hill, Botanist, SCNPS