Liatris aspera aka Tall Blazing Star

Liatris aspera, or rough blazing star, belongs to the daisy family. Its native range spans southeastern Canada and central and eastern America. This perennial grows from a corm and forms upright clumps. In the wild, it grows in prairies, glades, and open woods. It also grows in meadows and beside roads and railways. Its rough leaves explain the species name.

Most garden plants reach 2–3 feet [0.61–0.91 metres] tall. They spread about 1–1.5 feet [0.30–0.46 metres] wide. Some plants reach 5 feet [1.52 metres]. RHS gives a larger range, reaching 8.2 feet [2.5 metres]. Green to dark red stems bear short, stiff hairs. The green leaves form a tuft at the base. These narrow, lance-shaped leaves reach 1 foot [0.30 metres] long. Leaves grow smaller and narrower farther up the stem. They have smooth edges, slight hairs, and a rough feel. The plant loses its leaves at the season’s end.

Purple flower heads crowd the upper stems in long spikes. Small disc flowers give each rounded head a fluffy look. Flowering runs from August through October in the American sources. Chicago also records blooms in July. Flowers open from the top of each spike downward. Missouri Botanical Garden notes that many open around the same time. The stems make useful cut flowers for indoor arrangements. Dry fruits called achenes appear in September and October. Their gray-brown hair tufts help the wind carry them away.

Grow this plant in full sun and well-drained soil. It also accepts some shade, according to North Carolina State Extension. It tolerates poor, dry, and shallow rocky soils. It withstands drought, summer heat, and humid weather. Acidic sandy or rocky soil suits it well. RHS also lists neutral and alkaline soils as suitable. Avoid wet ground in winter, which can cause root rot. American sources list USDA zones 3–8; Chicago extends this to 9. RHS rates its UK hardiness as H4. Taller stems may need stakes, chiefly in windy sites.

Use rough blazing star in borders, rock gardens, or wildflower meadows. Its blooms draw butterflies and other pollinators. Birds feed on its seeds, and Chicago reports deer resistance. Serious pest and disease problems are uncommon. Rust and leaf spot can still occur. Sow seed in autumn or divide plants in early spring. Cut stems to ground level when the growing season ends.