Poaceae (Grass family)
Class B-Designate Noxious Weed
Originally from North Africa, Asia and Europe, Ravenna grass has been in the horticultural trade in the U.S. since at least 1921. Prized by gardeners for its dramatic display sustained through four seasons, it is also referred to as plume grass or hardy pampus grass, although it is unrelated to pampus grass. This tall ornamental plant has escaped cultivation and has spread as a noxious weed along the banks of the Columbia River, in seasonal wet areas, waste ways, and ditches and roads of Franklin County.
Ravenna grass has long cane-like stalks that reach heights of 6-12 feet with a basal area several feet in diameter. A key identifying characteristic is the thick, white mid-vein on the upper side of basal leaves. Stalks often turn red in midsummer prior to the formation of plumes in the fall. The plumes develop multiple seed heads, which produce thousands of seeds that are lightweight and dispersed by wind and water.
Ravenna grass germinates in a wide variety of habitats. In moist areas, basal leaves crowd out native and desirable species, creating habitat for rodents and acting as a physical barrier to water flow. Established stands increase fire risk. Ravenna grass root systems will lift concrete. Landscapers should not plant this species, which is under consideration for the state quarantine list, and should seek alternative, non-invasive ornamental grasses in its place.
Download our printable PDF with more information about Ravenna grass and best management practices for controlling it.
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