Umbrella Flatsedge
Cyperus diandrus
Last reviewed: June 2026
Light
full sun
Water
medium
Size
8"–24" H × 4"–12" W
Bloom
Jul, Aug, Sep
Native to
AL, CT, DE, IA and 19 more states
Cyperus diandrus is a small annual sedge that forms compact clumps with thin, grass-like foliage. It produces small clusters of brownish flower heads from summer through early fall. This plant thrives in full sun with consistent moisture.
In an HOA neighborhood
Umbrella Flatsedge takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Looks very much like a weed or wild grass
- Annual nature means gaps in coverage
- Inconspicuous flowers lack ornamental appeal
Wildlife value
This sedge provides seeds for small birds and offers nesting material. The dense growth habit can provide shelter for beneficial insects.
Common questions
- How much sun does Umbrella Flatsedge need?
- Umbrella Flatsedge grows best in full sun conditions.
- When does Umbrella Flatsedge bloom?
- Umbrella Flatsedge blooms in July, August, and September.
- Where is Umbrella Flatsedge native?
- Umbrella Flatsedge (Cyperus diandrus) is native to AL, CT, DE, IA and 19 more states, per the USDA PLANTS Database and regional native plant society lists.
- Is Umbrella Flatsedge HOA-friendly?
- Umbrella Flatsedge takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow Umbrella Flatsedge? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
Not sure where to start? Take the 2-minute yard quiz