Salt Meadow Cordgrass

Spartina patens

WA A Poaceae
Data Maturity Baseline

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

Type
perennial herb
Origin
The Atlantic coast from Canada to the Caribbean and Central America.

Identification

Growth Habit

Salt meadow cordgrass is an upright, rhizomatous grass, 1 to 4 feet tall. The plant forms dense stands.

Leaves

The leaves are hairless, blades are 3.9-19.7 inches (10-50 cm) long, by 0.002-0.16 (0.28) inches (0.5-4(7) mm) wide. When young the leaf blades are in-rolled and have ridges. The ligules consist of a fringe of hairs, 0.02 inches long.

Flowers

Flowers occur in two to several spikes that are pressed together to somewhat spreading.

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

As its common name implies, it dominates the upper salt marsh. It also will colonize on sand dunes, swale grasslands, sand flats and coastal scrublands. Please click here to see a county level distribution map of salt meadow cordgrass in Washington.

Spread Mechanisms

seed vegetative fragments

Reproduction

Salt meadow cordgrass reproduces mainly by its rhizomes, although it does produce viable seed.

Regional Notes — Puget Sound

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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.

Biological Control

  • Several insects feed on Spartina patens in its native range. Currently, the distribution of S. patens in Washington is too small to require the use of classical biological control.