Blue-eyed grass

Sisyrinchium augustifolium

Photo: Blue-eyed grass

General description

Common Name: blue-eyed grass
Type: Herbaceous perennial
Family: Iridaceae
Zone: 4 to 9
Native Range: Southeastern United States
Garden Location: Enterprise Rent-A-Car Flower Borders
Height: 1.5 to 2 feet
Spread: 0.5 to 1 feet
Bloom Time: May to June
Bloom Color: Blue
Bloom Description: Blue
Sun: Full sun
Water: Medium
Maintenance: Medium
Flowers: Showy Flowers
Uses: Cut Flower, Groundcover, Will Naturalize


Best grown in medium moisture, well-drained soil in full sun. Tolerates light shade. Prefers consistently moist soils that do not dry out, but drainage must be good. Will freely self-seed in optimum growing conditions. Plantings may be sheared back after bloom to avoid any unwanted self-seeding and/or to tidy foliage for remaining part of the growing season. Plants may need to be divided every 2-3 years to keep plantings vigorous.

Noteworthy Characteristics

Though their foliage is grass-like, the blue-eyed grasses belong to the iris family not the grass family. Sisyrinchium angustifolium is noted for its violet-blue flowers and branched flowering stems. It is native to Missouri where it occurs in damp open woods, slopes and along stream banks throughout much of the State. It is a clump-forming perennial that features a tuft of narrow grass-like leaves (to 3/16" wide) typically growing to 12" (less frequently to 20") tall. Clusters of violet-blue flowers (to 1/2" across), each with 6 pointed tepals and a yellow eye, appear in spring on stalks growing from leaf-like bracts atop usually branched flowering stems which are distinctively flattened.Sisyrinchium campestre, also a Missouri native, features pale blue to white flowers atop unbranched flowering stems. S. angustifolium includes plants formerly classified as S. bermudianum.


No serious insect or disease problems.

Garden Uses

Best naturalized in informal garden areas such as cottage gardens, woodland gardens, wild gardens or native plant areas. Also effective in border fronts and rock gardens. Also effective as an edger for paths or walkways.


1 - 1000 cm