Big Blue

big bluestem,
tall bluestem,
Andropogon gerardii


When you read the word “prairie”, what do you think of? Buffalo roaming the grasses of the Great Plains? Amber waves of grain?

Prairies are temperate grassland ecosystems, as are the pampas of South America and the steppes of Eurasia, and “prairie” is most often used to describe very large areas. But there are smaller prairies in different parts of the US, including riverside prairies and bedrock terrace prairies right here in the Potomac Gorge. And on some of those, one of the dominant forms of vegetation is big bluestem, also the dominant grass species of the tallgrass prairies of the midwest. It can be found in most of the rest of the US (except the far west) and Canada, as well.


Big bluestem is a clump forming grass, growing to six feet tall and taller when in flower. Given the right conditions (plenty of water) it can also be a sod-forming grass, but you won’t find that in the Gorge. It has blue-ish stems that turn red in autumn. Dainty yellow flowers appear in August and persist through the winter.

Big bluestem is considered weedy by some authorities, but the terrain and hydrology of the bedrock terraces in the gorge limit its growth there. Look for isolated clumps in areas of full sun well above mean water level.