A True Blue Flower

Posted: May 3, 2012

I went for a walk last Sunday, enjoying bright sunshine and blue skies, and encountered a delightful but little known native wildflower, blue-eyed grass, blooming along the way. It’s not really a grass, being a member of the Iris family, but it really does have a true blue flower. For me, that’s reason enough to recommend it for the garden, although some garden writers dismiss it as too inconsequential for inclusion in the garden. Often, the beauty of a plant is in the details.

Blue-eyed grass is in the genus Sisyrinchium (pronounced siss-sea-rinch-ee-um), a group of anywhere from 50 to 150 species, most native to South America and some to North America. The classification of these species is very confused, and it can be very difficult for botanists to accurately identify a particular species.
The blue-eyed grass that is common throughout the eastern United States, ranging from Newfoundland west to Minnesota and south to Texas and Florida, is identified as Sisyrinchium angustifolium, or narrow-leaved blue-eyed grass.
This is apparently the same species as the blue-eyed grass I saw when I visited Bermuda a few years ago. It is widespread on that tiny island in the Atlantic, growing on rocky seashore banks, and there it is called Bermuda Iris, Bermuda Grass, or just Bermudiana. This is the plant that was first described by Linnaeus as Sisyrinchium bermudianum.
Not all blue-eyed grasses have blue flowers. There are species native to the western United States and to South America that have yellow, purple, white, or pink flowers.  There are also some cultivated varieties, such as ‘Lucerne’, that have larger purplish-blue flowers than the species, and for that reason may be deemed more garden-worthy.
The foliage of blue-eyed grass resembles that of a diminutive iris: narrow blue-green blades, arranged in fans rising from a tiny rhizome, forming a tufted grass-like clump about 10 to 12 inches in height and width. It grows in moist open meadows or fields, or in damp sunny patches along woodland edges, although it is very adaptable to much drier soil conditions. On my walk, I found it growing in both a moist sunny meadow and on a thin shaly bank.
The ribbon-like foliage is attractive all summer and is often semi-evergreen; and the fans of foliage continue to grow through fall and into winter if the weather stays mild. In the garden, it needs well-drained soil, of average fertility, which keeps its growth low and compact. It is subject to crown rot if the soil remains wet over winter or if it is mulched too heavily.
Blue-eyed grass begins blooming in early May and, although individual flowers are small and last less than a day, the plant continues to bloom for several weeks; it may also bloom sporadically in late summer and early fall. The flowers emerge in small clusters from flattened stems rising a few inches above the foliage. They remain tightly closed until warmed by the rays of the sun, when they open wide to reveal a true blue star with six notched petals, veined in deeper violet and with a contrasting bright yellow throat, or “eye”. So you’ll only see the open flowers when it’s sunny, and then it looks like a blue haze drifting low across the meadow.
The blue flowers are followed by dangling green seed capsules which gradually mature to brown, dispersing tiny black seeds that pop up as new plants about the garden. It can be a prodigious self-seeder, but unwanted plants are easy to pull so as not to become a nuisance.
In the garden, blue-eyed grass works well as a rock garden specimen, massed at the base of a stone wall, or as an edging plant along a path or border. And while the individual flowers are fleeting, they are, like a true-blue friend, worthy of your attention.