Umbrella papyrus

Aquatic perennial · Perennial

Cyperus alternifolius

Umbrella papyrus

Also known as: Cyperus involucratus, Cyperus flabelliformis, Cyperus alternifolius subsp. flabelliformis

An elegant, water-loving sedge with tall green stems topped by umbrella-like whorls of narrow leafy bracts.

  • Full sun, Partial shade
  • 0.6–1.5 m (2–5 ft)
  • 0.5–1 m (2–3 ft)
  • H1c · Zone 10
  • June–September
  • Evergreen

Overview

Native to Madagascar and nearby islands, with a closely related form widespread in tropical Africa and Arabia, the umbrella papyrus forms dense clumps of upright, three-angled green stems. Each stem ends in a flat, spoked whorl of narrow, grass-like bracts, like the ribs of an umbrella, with small brown flower clusters in summer. It grows naturally in marshes and along streams, so it thrives in permanently wet soil or standing in shallow water. It is frost tender (minimum about 5°C / 41°F), so in climates with frosty winters it is grown as a pond-side or patio plant for summer and moved indoors as a houseplant for winter; in frost-free climates it can be grown outdoors all year. It has become a weed of waterways in some warm regions, including parts of Australia and the Pacific. Plants sold under this name are often Cyperus involucratus, which many botanists now treat as part of the same species.

At a Glance

Sun Full sun, Partial shade
Height 0.6–1.5 m (2–5 ft)
Spread 0.5–1 m (2–3 ft)
Hardiness H1c · Zone 10
Flowers June–September
Soil Clay, Loam, Sand
Moisture Wet
Habit Clump forming, Upright
Water High
Maintenance Easy

Growing Conditions

Min. Temperature 5°C (41°F)
pH Range 5.5–8
Fertility Fertile
Drainage Moderate

Aspect Suitability

  • East-facing
  • South-facing
  • West-facing

Site Tolerance

  • Wet soil

Soil Tolerance

  • Clay
  • Sandy
  • Loam
  • Acid
  • Neutral pH
  • Alkaline

Foliage

Cyperus alternifolius (Umbrella papyrus)
Persistence Evergreen
Colour Green
Leaf shape / texture linear_whorled
  • Architectural foliage

Foliage interest: 12 months of the year

Seasonal Timeline

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flowering
Foliage
Propagate
  • Flowering Jun Jul Aug Sep
  • Foliage 12 months of the year
  • Propagate Apr May Jun Jul

How to propagate

Ways to grow more Umbrella papyrus: the usual steps for each method.

Division Apr Easy

You'll need: A garden fork or spade (two forks back to back help with big clumps) and a sharp knife.

  1. Water the plant well the day before.
  2. Dig up the whole clump with a fork, keeping as much root as you can.
  3. Split it into pieces about the size of your fist, each with healthy roots and shoots: pull them apart by hand, or cut tough clumps with a knife or spade.
  4. Throw away any old, woody middle.
  5. Replant the pieces straight away at the same depth, and water them in well.
How long
Settles in within a few weeks.
It's worked when
Fresh new growth within a few weeks.
Then
Water in dry spells for the rest of the season.
Leaf cuttings Apr–Jul Easy

You'll need: A healthy leaf, a clean knife, a pot of gritty compost or cactus compost.

  1. Take a healthy, full-grown leaf (for succulents, twist it off cleanly).
  2. For succulents, leave it a few days for the cut end to dry; for others, use it straight away.
  3. Rest it on, or push its base just into, the compost.
  4. Keep it warm and bright, out of direct sun, and only just moist.
How long
Tiny plantlets in about 3 to 8 weeks.
It's worked when
Small new plants forming at the base of the leaf.
Then
Pot the little plants up on their own once they're big enough to handle.
From seed Apr–May Easy

You'll need: Seed compost, a seed tray or small pots, labels, and a clear lid or plastic bag.

  1. Fill a tray or pots with seed compost, level it and firm it gently.
  2. Water the compost and let it drain.
  3. Sow the seeds thinly on top. Cover them with a fine layer of compost or vermiculite about as deep as the seed is big; leave tiny seeds uncovered.
  4. Label them, cover with a clear lid or bag, and keep them somewhere bright but out of hot sun.
  5. Keep the compost just moist, and take the cover off once seedlings appear.
How long
Usually comes up in 1 to 3 weeks.
It's worked when
Seedlings with their first pair of leaves.
Then
When each has its first true leaves, prick them out into their own small pots, holding them by a leaf, never the stem. Harden them off for a week or two before planting out.

Divide clumps in spring. Alternatively cut off a leaf whorl with about 5cm of stem, trim the bracts by half and float it upside down in water; roots and new shoots form within a few weeks.

Maintenance Calendar

  • Mar Cut old, browning stems out at the base to make room for fresh growth
  • May Move pots outside once nights stay above about 10°C (50°F), or stand them in a pond margin
  • Jul Never let the compost dry out, and standing the pot in water is the easiest way to keep it constantly wet
  • Sep Bring plants indoors to a bright spot before the first frost, keeping the compost moist

Garden Design

Works well in: Japanese / Zen, Modern / Contemporary, Tropical / Exotic

Stand the pot in a shallow saucer or sink it into a pond margin with water just over the pot rim; the umbrella heads look striking against plain walls or water.

Companion planting: Colocasias, Cannas, Ferns, Marginal water plants

Wildlife Value

  • Shelter

Listed as an invasive non-native plant in the UK: never let it spread into the wild.

Safety

Not known to be toxic. It can spread along waterways in warm climates and is an environmental weed in parts of Australia and the Pacific, so never plant it into natural ponds or streams there.