Posted by Jessie Jacobson on Jan 1st 2024

Sisyrinchium (Blue-eyed Grass) 

Dainty clusters of star-shaped flowers in shades of blue and violet sit atop the narrow grass-like leaves of Sisyrinchium angustifolium, commonly called Blue-eyed Grass, creating a delightful garden dance. Despite its common name, Blue-eyed grass is not really a grass, but a member of the Iris family, Iridaceae that makes a lovely garden border or adds texture and interest to the landscape.

Native to the central part of North America, from Texas to Manitoba, Blue-eyed grass cultivates best in full sun though it can take some shade with lower flower production. It prefers moist, well-drained soil and is easy to grow even in relatively poor soil. Yearly fertilizing is not necessary, but an occasional addition of organic compost is recommended. At maturity, Sisyrinchium angustifolium grows 12 to 18 in tall and wide. It spreads by both rhizomes and seed, so to keep the Blue-eyed grass manageable, divide the plant every three years and cut off the seed heads. Sisyrinchium angustifolium can also be left to naturalize by leaving the seed heads on and allowing the plant to take root wherever it chooses. Blue-eyed grass is a fan of birds, butterflies, and pollinators, but not a favorite of deer and rabbits. Fortunately, it is not prone to many diseases or insect pressures, however Blue-eyed grass can suffer from root rot under some conditions. It is best to avoid this by keeping mulch at least 3 inches away from the base of the plant and placing the plant in well-drained soil.

Blue-eyed grass blooms in late spring to early summer with small 6-pointed flowers emerging on spikes above its grass-like foliage. An interesting feature of this plant is that they open in the morning sunlight and close when it’s cloudy or in the late afternoon. As their name suggests, the flowers are mostly shades of blue or violet with yellow centers. The leaves are sword shaped and fan out like others in the Iris family. Blue-eyed grass can be used as a border, an accent plant in a perennial bed, or naturalized in a woodland area.

Happy planting. See you at Tonkadale.