Common Name: umbrella plant
Type: Rush or Sedge
Family: Cyperaceae
Zone: 9 to 12
Height: 1.00 to 2.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: Seasonal bloomer
Bloom Description: Green to brown
Sun: Full sun to part shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Annual, Water Plant, Naturalize, Rain Garden
Flower: Insignificant
Leaf: Evergreen
Other: Winter Interest
Tolerate: Erosion, Wet Soil
Culture
Winter hardy to USDA Zones 9-12 where is easily grown in wet, boggy soils in full sun to full shade. Perhaps best in full sun to part shade. Plants tend to be more compact in sun and more open, larger-leaved and taller in shade. This is an amphibious sedge which grows well in shallow standing water. Plants are tender perennials that are intolerant of frost. Plants in Zones 8-9 will die back with frost, but may survive the winter and put out new foliage in spring if the roots remain unfrozen. Plants may be grown in containers at the margins of water gardens, pools or ponds.
In the St. Louis area, these plants are tender perennials that must be brought indoors in fall before first frost for overwintering in a sunroom or greenhouse. Containers can be brought indoors if not too large. Another option is to divide plants and pot up the divisions for overwintering indoors. When overwintering, set the container in a saucer filled with water, and place the container and saucer near a bright sunny window. Add water to the saucer as needed.
Rather than overwinter indoors, plants may be grown as if they were annuals by letting them die each winter and replacing them each spring.
In warm frost-free climates, this sedge is weedy bordering on invasive. It can spread aggressively by self-seeding and rhizomes. Planting in containers helps prevent some unwanted spread. Florida Exotic Pest Plant Council has designated this plant as Category II: An invasive exotic that has not yet altered plant communities to the extent it would qualify as Category I.
Noteworthy Characteristics
Cyperus involucrata, commonly called umbrella plant or umbrella sedge, is a rhizomatous, evergreen, densely-clumping, tender perennial sedge that typically grows to 3-6’ tall in frost free areas, but to 2-3’ tall where not winter hardy and grown as an annual. It is probably native to boggy areas and lake/stream margins in Madagascar (Malagasy Republic), but early on naturalized throughout eastern Africa. It has been introduced in many tropical, sub-tropical and warm temperate areas around the globe over time including the southern U.S. where it has escaped gardens and naturalized primarily in wet disturbed sites, water margins, ditches and swampy areas from Florida along the Gulf Coast to Texas plus Arizona, California and Hawaii.
This sedge is ornamentally grown for its showy green bracts and not for its somewhat insignificant flowers and fruits. Erect triangular stems rise up from a network of short woody rhizomes. Each stem is topped by a whorl-like cluster of 10-25 thin slightly downward-arching leaf-like bracts (each to 6-15” long) which form a showy umbrella-shaped rosette. Bracts look like leaves, but they are not. The true leaves of this sedge are inconspicuous bladeless sheaths which wrap the stem bases.
Dense clusters (15 to 25) of flattened flower spikelets (6-30 tiny florets per spikelet) rise above the umbrella-like bracts for bloom summer to fall. Flower spikelets emerge green but turn reddish-brown as they mature. Flowers are followed by small dark brown 3-angled nut-like fruits.
Genus name comes from the Greek word kypeiros which was the name given to some local sedges.
Specific epithet comes from the Latin word involvere meaning to wrap in reference to the involucral bracts on this sedge.
‘Gracilis’, sometimes commonly called miniature umbrella plant, is a dwarf cultivar that is noted for having very narrow leaf-like bracts. It typically matures to 1-2’ tall. It is less likely to flower than species plants and is therefore less likely to self-seed. It will not survive winter if temperatures dip below 25 degrees F. It typically grows as an annual north of USDA Zone 9, but potted plants may be brought indoors in winter. Cultivar name from Latin means slender or graceful.
Problems
No serious insect or disease problems. Not winter hardy to St. Louis area.
Uses
Accent for water gardens, bogs or pond/stream peripheries. Patio containers/tubs. Houseplant. Trimmed umbrella stems may be added to flower arrangements.