Blue Eyed Grass Weed

Blue Eyed Grass Weed

Blue Eyed Grass Weed

The line separating what is a weed and what isn’t often comes down to where the “weed” is growing and who is managing the area it’s growing in. Blue Eyed Grass (Sisyrinchium rosulatum), one of the most complained about lawn weeds this winter/spring falls squarely in that category! Native plant enthusiasts and homeowners looking to add native wildflowers to their landscape value the plant for its low maintenance, star-shaped blue blossoms in spring. Professional and home turfgrass managers, however, loathe the plant as it masquerades as grass to the untrained eye, looks messy in the cool months, and can displace turf during spring green up. While Blue Eyed Grass can be a pretty landscape plant, our focus today is on learning why it is such an annoying weed in turfgrass areas and exploring control options if it becomes a problem!



For starters, Blue Eyed Grass (BEG) is not even a grass, though it does look an awful lot like one! It is actually a member of the Iris family and is more closely related to spring beauties like Gladiolus, Iris, and Crocus than any turfgrasses. The flowers, appearing late March through April, are a dead giveaway that we aren’t dealing with a grass, as are the flat leaves arranged in bunched fan-shaped rosettes. BEG is considered a winter annual plant in Florida, meaning it sprouts from seed in the fall, grows through the winter, then flowers and sets seed in the spring. Because it grows while lawn grass is dormant, it is very noticeable during its entire lifespan. Though BEG can tolerate a range of soil types, it prefers to grow in moist areas, making it right at home in Panhandle lawns and landscapes in the winter as we experience regular to excessive rainfall throughout our cool season.While Blue Eyed Grass can be an attractive addition to the landscape, it is never welcome in turfgrass! To prevent this and weeds from becoming a problem, use smart cultural practices to maintain a healthy turf and make timely herbicide applications when needed. For more information on controlling Blue Eyed Grass and other winter weeds, contact your local UF/IFAS Extension office!

Despite it’s common name, blue-eyed grass is not a grass. The genus Sisyrinchium is a large group of annuals and perennials in the iris family (Iridaceae). But many species are low growing with narrow leaves that appear grass-like and many grow in grasslands. All are native to North or South America. Most are not well known and only a few are used as ornamentals. The taxonomy of the group is quite confused, so the number of species varies from 50 to 150, depending on which classification system is used. Some species have many natural variants that were likely mis-named as species – so more research is needed to figure out the true relationships.Sisyrinchium plants all have clumps of stiff, upright, sword-shaped leaves held in a fan shape – just like most of their relatives in the iris family. However, the individual leaves are usually narrower than that of a typical iris plant, giving a grass-like appearance. They grow from thin rhizomes that gradually spread outward from the clump. Some species are evergreen, while many others — especially in colder areas — die back to the ground in winter. In spring or summer small flowers appear on spikes at or just above the foliage. Individual flowers emerge from a green spathe slightly wider than the supporting branch. (Source: hort.extension.wisc.edu)


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