Big Bluestem is the tallest native grass in the area, reaching maximum heights of 8 feet. The stems turn a blue/purple color in late summer and into fall which can lend a dramatic effect to a prairie or garden planting. Big Bluestem matures rather quickly, ev ... en from seed, with full height reached in two seasons if they are well cared for. It is a lovely addition to most gardens in full to part sun and can tolerate most soils save the very dry. Just remember that this one gets very big, but it grows just fine if crowded.