Umbrella papyrus

Sun

Full sun to partial shade; light afternoon shade is useful in very hot climates.

Water

Keep constantly moist to wet. Established plants tolerate shallow standing water; never let container compost dry out.

Soil

Rich, moisture-retentive loam or aquatic planting soil; tolerates heavy soil and a broad range of pH.

Height

3-6 ft (0.9-1.8 m)

Spread

2-3 ft (0.6-0.9 m), widening through rhizomes

Flowers

Summer to autumn; small greenish flowers mature to brown in clusters above the umbrella-like bracts.

Foliage

Evergreen. Upright, mostly leafless green stems carry flattened, narrow green bracts arranged like umbrella spokes.

Growth

Fast in warm, wet conditions.

Care needed

Medium

• Heat tolerant
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   2.8 ft (0.84 m)

3. After 2 years

   4 ft (1.4 m)

   full size

About 2 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Invasive in

the US and Australia

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Fast

• Keep the root ball wet; stand containers in a deep saucer of water and replenish it frequently.
• For pond growing, position the crown at water level or under up to 4 in (10 cm) of water.
• Feed container plants monthly with a balanced liquid fertiliser during active growth; use aquatic fertiliser in ponds.
• Divide crowded clumps in spring and replant the divisions promptly into wet soil.
• Move containers indoors before frost and keep them in bright light, preferably above 50°F (10°C).
• Use a solid container where spreading roots could escape into drains or natural waterways.

Pruning. Cut yellow, brown or broken stems off at the base whenever they appear; shortened stems do not regain their umbrella tops. In spring, remove any winter-killed growth once new shoots emerge.

Spring

Divide congested plants and repot into larger, watertight containers if needed.

Late spring

Move overwintered plants outside after frost danger has passed, gradually increasing their exposure to sun.

Summer

Check water levels frequently and feed actively growing container plants monthly.

Late summer

Remove flower clusters before seeds ripen where escape or self-seeding is a concern.

Autumn

Bring containers under cover before frost in cold climates.

Winter

Keep sheltered plants bright and wet, stop routine feeding, and remove dead stems.

• Use a contained clump at a pond edge to add height without a dense screen.
• Place in a watertight courtyard container as a simple architectural focal point.
• Combine with cannas and elephant ears for contrasting leaf shapes in a wet tropical-style planting.
• Repeat containers beside a terrace or water feature for a rhythmic, upright accent.

Garden styles it suits: Architectural minimal, Modern tropical, Tropical, Bog garden, Modern courtyard and Green on green.

Plant it with: Canna, Elephant ears, Pickerelweed, Japanese iris, Water lilies and Soft rush.

Wildlife: Dense clumps provide cover and resting places for small pond animals and insects. The flowers are wind-pollinated and are not a significant nectar source.

• Brown tips and collapsing stems usually follow drying out: soak the root ball and maintain a steady water supply.
• Spider mites can cause pale, stippled growth indoors: rinse stems and bracts thoroughly and treat persistent infestations with insecticidal soap according to its label.
• Aphids may gather on tender shoots: wash them off with water or use insecticidal soap.
• Frost blackens stems and can kill the roots in containers: move plants into frost-free shelter before cold weather.

Safety information for umbrella sedges is inconsistent, partly because several unrelated plants share the common name. Treat stems, bracts and roots as potentially harmful to cats and dogs if eaten; vomiting or diarrhoea may occur. Toxicity to horses and people is not well established, so do not use it as food or animal forage.

Where it spreads. Spreads by rhizomes and seed and can form dense colonies in wet ground. It is invasive in Hawaii and parts of Florida, and is an environmental weed in parts of Australia, including Queensland and New South Wales. Keep it contained and never discard plants or seed heads into waterways.

• Papyrus (Cyperus papyrus)

  Usually much taller, with large, airy heads of numerous fine, thread-like rays rather than a simple whorl of broad, flat bracts.

• Dwarf umbrella sedge (Cyperus albostriatus)

  Usually shorter and has conspicuous broad leaves near the base as well as broad bracts around its flower heads.

The species name involucratus refers to the whorl of bracts surrounding the flower clusters, which also gives the plant its umbrella-like appearance.

Propagation. Divide rooted clumps in spring. Alternatively, cut a healthy stem with its umbrella intact, shorten the bracts, and place the umbrella upside down in water with the stem pointing upward; plant it once rooted shoots develop.

Accepted botanical name

Cyperus involucratus

In the US and Canada

Introduced in Hawaii, the lower 48 states, Pacific Basin, Puerto Rico and US Virgin Islands.

Sources: GBIF (CC BY 4.0) and USDA PLANTS. The care and design notes are LandscapeGPT's own.