Slough sedge (Carex obnupta)




     Washington, Oregon, and California (5)


Climate, elevation

     Moist, low elevation (4), or can be found in higher elevation forested wetlands (1)


Local occurrence (where, how common)

     Wet prairies and meadows, sloughs, marshes, lake shores, forested wetlands (1,4); forms dense stands in standing water (1), most common of the evergreen sedges in local valleys and floodplains (4)


Habitat preferences

     See previous


Plant strategy type/successional stage (stress-tolerator, competitor, weedy/colonizer, seral, late successional)

     Able to tolerate fluctuating water levels and brackish conditions


Associated species

     Oregon ash (Fraxinus latifolia), skunk cabbage (Lysichiton americanum), salmonberry (Rubus spectabilis) (4)


May be collected as: (seed, layered, divisions, etc.)

     Rhizome/culm plugs



Collection restrictions or guidelines

     Collect seeds in late summer to early fall

     Collect culms in fall (best to use young plants)


Seed germination (needs dormancy breaking?)

     Soak seeds in water for 24 hours (5)


Propagation recommendations (plant seeds, vegetative parts, cuttings, etc.)

     Sow seeds on surface of growing medium in flats in spring (5)

     Seeds germinate 30 days after sowing (5)

     Transplant germinated seedlings to individual containers (2x7 in. tubes) for outplanting (5)

     Harvested culms can be planted into larger containers for later division


Soil or medium requirements (inoculum necessary?)

     Growth medium for germination flats should be peat, perlite, major and minor nutrients, gypsum, and dolomitic lime mix (5)

     Growth medium for transplants should be a standard potting mix consisting of peat, fir bark, perlite, and sand (5)


Installation form (form, potential for successful outcomes, cost)

     Container plug with established seedling (usually after two months)  

     Harvested culms

     Seeds can also be scattered on site in the fall, but they may be washed away by fluctuating water levels (2)


Recommended planting density

     Either one container plug or three culms on 20 centers


Care requirements after installed (water weekly, water once etc.)

     Soil must be kept moist (5)


Sources cited

1.      Guard, B. Jennifer. Wetland Plants of Oregon and Washington. Lone Pine Publishing. Vancouver, B.C. 1995.


2.      Hansen, W.W. 2003. Native Plants of the Northwest, Native Plant Nursery & Gardens.


3.      Leigh, Michael. Grow Your Own Native Landscape. Native Plant Salvage Project, WSU Cooperative Extension-Thurston County. Revised edition, June 1999.


4.     Pojar, Jim and Andy MacKinnon. Plants of the Pacific Northwest Coast-Washington, Oregon, British Columbia and Alaska. B.C. Lone Pine Publishing. 1994.


5.      Young, Betty. 2001. Propagation protocol for production of container Carex obnupta Bailey plants (Deepot 16); Golden Gate National Parks, San Francisco, California. In: Native Plant Network. URL: (accessed 18 April 2003). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery. 


Data compiled by:

        Crystal Elliot, 4/17/03