Slough sedge
Carex obnupta
Last reviewed: September 2026
Slough sedge (Carex obnupta) is a perennial grass native to CA, OR, WA. It blooms in April, May, and June. The flowers draw wind pollinated.
Toxicity unknown
Slough sedge (Carex obnupta) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
high
Size
24"–48" H × 18"–36" W
Bloom
Apr, May, Jun
Native to
CA, OR, WA
Pollinators
wind pollinated
Before you buy
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Slough sedge is a coarse, clumping evergreen sedge with dark green arching leaves and inconspicuous wind-pollinated flower spikes. It grows in wetlands, marshes, and along stream edges, tolerating standing water.
Growing Slough sedge
Grow Slough sedge in full sun and high water. Mature plants reach 24 to 48 inches tall and spread 18 to 36 inches wide.
Wildlife value
While its flowers offer little to pollinators, the dense foliage provides cover and nesting material for wetland birds and small wildlife, and the seed heads feed songbirds.
Common questions
- How much sun does Slough sedge need?
- Slough sedge grows best in full sun conditions.
- When does Slough sedge bloom?
- Slough sedge blooms in April, May, and June.
- Where is Slough sedge native?
- Slough sedge (Carex obnupta) is native to CA, OR, WA, per vouchered herbarium specimen records and regional native plant society lists.
- What pollinators does Slough sedge attract?
- Slough sedge draws wind pollinated.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
Ready to grow Slough sedge? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.