Smooth cordgrass can spread by seed, rhizome, or vegetative fragmentation.

Where does it grow?

What is the distribution in Washington State?

Click on map to enlarge.

• Smooth cordgrass has been documented Clallam, Grays Harbor, Pacific, Snohomish, Skagit counties. It has also been reported in Kitsap, Mason and Jefferson counties.
• Distribution map based on 2003 data.

How do I control it?

General control methods:

Cultural: Diking can be used as a containment measure, since dikes confine the lateral spread of rhizomes:

• Dikes tidal action, inhibiting nutrient flow and oxygen exchange. 
• Dikes can be used to flood areas, which will eventually bring about Spartina death
• This method will also kill other species that cannot tolerate prolonged flooding

Herbicide: Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

Mechanical:

• Seedlings can be pulled out effectively, care should be taken to remove both shoots and roots.
• Covering small clones with woven geotextile fabric has been successful on Spartina.
• 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 mowings will be required for three or four years

Biological: Several insects feed on Spartina in its native range. Ergot fungus, Claviceps purpurea,has potential as a biocontrol agent, but it may also feed on other types of grasses. More research is needed before biocontrols can be introduced in Washington.

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