Dense Blazing Star (Liatris spicata) or Marsh Blazing Star is a tall, upright, clump-forming perennial which is native to moist low grounds, meadows and marsh margins. It typically grows 2-4 feet tall in cultivation, but can reach a height of 6 feet in some parts of its native habitat. Features terminal spikes of sessile, rounded, fluffy, deep purple flower heads (each to ¾-inch across) appearing atop rigid, erect, leafy flower stalks. One or more stalks arise from a basal tuft of narrow, grass-like, medium green leaves (to 12 inches long). Stem leaves gradually decrease in size toward the top. Blooms in summer. With each flower head having only fluffy disk flowers (resembling blazing stars) and no ray flowers. The feathery flower heads of liatris give rise to another common name of Gayfeather. Afterwards, the florets are replaced by small achenes with stiff bristles at their apices; these bristles are light brown. The root system consists of a corm with shallow fibrous roots. Colonies of plants are often formed by means of clonal offsets that involve the production of new corms.
Habitats include moist black soil prairies, moist sand prairies, prairie swales, edges of marshes and bogs, grassy fens, calcareous seeps, moist alkaline sandflats, and areas along railroads. This blazing star is found primarily in higher quality natural areas, especially where it is sandy.
Easily grown in average, medium, well-drained soils in full sun. Somewhat tolerant of poor soils, but prefers moist, fertile ones and generally performs better in moist soils than most other species of Liatris. Intolerant of wet soils in winter. Tolerant of summer heat and humidity. May be grown from seed, but is slow to establish.