Mature plants create a very architectural rounded mound of needle like, stiff, very pointy, dark brown to almost black tipped, pale green leaves. Over time pups (basal offshoots) appear creating tight colonies. Flowering can occure at any time on mature plants if conditions are right with a flower spike of up to 2 meters tall bearing reddish/ brown to purple blooms. It is non monocarpic so the main plant does not die after flowering unlike many agaves.
Hardiness wise we have had this survive in the South of England down to -5c for short periods. Could possibly tolerate lower on the odd occasion. The key to it's outdoor winter survival is very well drained soil and protection from excess winter wet. This is best done with either a well ventilated winter cloche, moving under a well lit covered area such as a south facing porch or possibly just by turning the pot on its side to keep direct rainfall from reaching the compost.