For those whose lawns are bermudagrass, centipede, St. Augustine or another warm-season grass, you have a yard full of brown at present. If you look closely you might see what appears to be another grass creeping into it. Where turf becomes thin, this little invader appears, but it’s usually unnoticed.
In about a month if you’re observant you’ll realize this plant isn’t a true grass after all. These prostrate light green stems sport pale blue flowers with darker throats. Three yellow tipped stamens surround a single greenish pistil. Some flowers are nearly white while others have more yellow in them. Plants continue to bloom throughout the spring. They are actually relatives of irises.
There are over 75 different species of blue-eyed grass. Some can get almost two feet tall and flower color can vary tremendously. Most live in dry sunny places, but a few species inhabit shaded swampy areas.
By far, the most common wild species we have is the annual blue-eyed grass (Sisyrinchium rosulatum). It actually is a short lived perennial in this range, not a true annual, but it spreads largely by seed as do most annual weeds.
This species was introduced from South America, but it has become well established along the coastal plain from North Carolina to Texas. It thrives in full sun on sandy soils and doesn’t require high fertility.
Plants rarely get taller than five or six inches. Most never achieve that height, since they have a running growth habit and get razed by lawnmowers regularly. Delicate flowers with six equal petals rarely get much more than a quarter inch in diameter.
Leaf texture is similar to St. Augustine grass and color closely mimics centipede. Plants blend in quite well, so I rarely find them objectionable in either turf. Once the grass greens up in spring most people likely won’t even notice the blue-eyed grass unless they see the flowers.
People who don’t like weeds in their lawn can attack blue-eyed grass in winter, when desired turfgrasses are dormant. If infestations are small, these weeds can be removed by hand, since they are quite easy to spot when the rest of the lawn is brown.
If you feel your lawn can’t coexist with blue-eyed grass and hand weeding is impractical, then chemical control is possible. Triazine herbicides are quite effective against it. Never exceed recommended rates. Pollution and turf injury can occur.
I know of no reports of this plant being desirable to eat, although many species of blue-eyed grasses have been used medicinally to treat diarrhea and other digestive problems. I also am unaware of any parts of it being poisonous either, although it would be if lawn chemicals were used recently.
I do think it has potential for ornamental use in rock gardens. Flowers are small, but they’re striking. They also bloom for a couple months and the creeping foliage adds interesting accent. Plants are easily transplanted as well as being prolific seed producers. They also tolerate dry conditions well. Maybe my students can propagate some for our spring plant sale.
Ted Manzer teaches agriculture in northeastern North Carolina.