Washington State Weeds

Common Cordgrass

common cordgrass

Spartina angelica • Class A

Family Name: Gramineae Family  (gram-IN-ay-ee)
Common: Poaceae family, True Grasses 
Genus: Spartina (spar-TEE-nuh)
Meaning: From the Greek meaning a cord made from this grass
Species: anglica (AN-glee-kuh)
Meaning: Of or from England

Common cordgrass is a highly invasive salt marsh grass. This stiff plant grows from 1 foot tall in the spring, up to heights of 6 feet in fall.

Young healthy green shoots and leaf sheaths are often streaked with red or purple just below the sediment surface.

Its leaf blades are flat and smooth on both upper and lower surfaces tapering to a small sharp tip and having concave sides just before the tip. 

It also has rows of hairs where the leaf meets the stem (ligules) that are up to a third of an inch long. 

Flowers grow in numerous clusters consisting of 4 to 18 inch long spikelets, with 3 to 30 spikes per per cluster. 

 Why Is it a Noxious Weed?

This cordgrass, like other non-native species of Spartina, traps sediment, builds marshes from the edge out, and overgrows native vegetation. It alters the native ecosystem and produces monocultures that have much less value as habitat for feeding and roosting of shorebirds and other wildlife.

Loss of beach habitat, navigation routes, and reduced water access are a result of the spread of Spartina. Therefore, activities, such as fishing, hunting, boating, bird watching, botanizing, and shellfish harvesting are also negatively impacted. 

Where Does it Grow?

Common cordgrass usually flowers after 1 or 2 years, in late July to September. Ripe seeds fall from October to January. Vegetative fragments may spread year round 


Seeds are spread by wind and water currents, but can also spread vegitatively by rhizomes and fragments that break off and move downstream. 

Control Options:

Pulling out seedlings is an effective method of control. Care must be taken to remove both shoots and roots. Once the plant begins to put forth new shoots, hand-pulling may break off portions of root, allowing the plant to re-sprout. Seedlings generally begin this process late in their first growing season. Repeated pulling will eventually kill small plants.

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. For clones under 10 feet in diameter, one to three mowings during the growing season may be effective. 

Since Smooth Cordgrass is found in aquatic areas, the use of an herbicide formulated for aquatic settings is required. Please note that aquatic herbicides are restricted for use in Washington State to licensed applicators only. 




More Information:

For more information on the noxious weed Download our Flyer or visit Washington State Noxious Weed Control Board Here


More Pictures:  

common cordgrasscommon cordgrasscommon cordgrass