Dense-Flowered Cordgrass
Spartina densiflora
Washington State Classification
Class A — Eradication Required Statewide
In general, the Spartina genus is considered highly invasive and one of the most aggressive worldwide.
Quick Reference
Identification
Growth Habit
Dense flowered cordgrass is a perennial salt tolerant grass that is upright in form, growing in dense tufted clumps.
Leaves
The blades are narrow, long and in-rolled. Blades are tough, grayish in color and 1/4 to 1/3 inch wide.
Flowers
The inflorescence is a spike, 2.4 to 11.8 inches long. The flowers are dense, compact and colorless.
Impact
In general, the Spartina genus is considered highly invasive and one of the most aggressive worldwide. Spartina displaces native species, destroys wildlife habitat, interferes with recreational activities and is difficult and expensive to control.
Ecology & Spread
Habitat
Dense flowered cordgrass grows in the upper intertidal zone, or mid to high marsh zones, near the mean high water mark, or just below it on open mud. Please click here to see a county level distribution map of dense flowered cordgrass in Washington.
Spread Mechanisms
Reproduction
Unlike other Spartina species, this species reproduces only by seeds.
"
Control Methods
Mechanical
- Seedlings can be pulled out effectively though care should be taken to remove both shoots and roots. Covering small clones with woven geotextile fabric has been successful on Spartina patens. Mowing infestations can contain growth, limit seed set, and eventually kill the plants. To be effective, clones must be mowed repeatedly, beginning with initial spring green-up and continued until fall die-back. In some cases, repeated mowing will be required for three or four years.