Arum lily

Marginal · Perennial

Zantedeschia aethiopica

Arum lily

Elegant white spathes over glossy arrow-shaped leaves, at home in a damp border or the shallow margin of a pond.

  • Full sun, Partial shade
  • 0.5–1 m (2–3 ft)
  • 30–60 cm (12–24 in)
  • H4 · Zone 8
  • May–July
  • Semi evergreen

Overview

Arum lily, also called calla lily, makes clumps of glossy, arrow-shaped leaves and tall stems carrying pure white funnel-shaped spathes around a yellow spadix in late spring and summer.

It is hardy to about −10°C (14°F), USDA zones 8–10, more so when planted in water, which shields the crown. In mild climates it stays evergreen; in hot climates give part shade. It is weedy in moist pastures in coastal California and southern Australia.

Grow in rich, moisture-retentive soil or in an aquatic basket up to 30 cm (12 in) deep.

At a Glance

Sun Full sun, Partial shade
Height 0.5–1 m (2–3 ft)
Spread 30–60 cm (12–24 in)
Hardiness H4 · Zone 8
Flowers May–July
Soil Clay, Loam
Moisture Boggy
Habit Clumping
Water High
Maintenance Easy

Growing Conditions

Min. Temperature -10°C (14°F)
pH Range 5.5–7.5
Fertility Fertile
Drainage Poor

Aspect Suitability

  • South-facing
  • West-facing

Site Tolerance

  • Wet soil

Soil Tolerance

  • Clay
  • Loam
  • Acid
  • Neutral pH
  • Alkaline

Foliage

Persistence Semi evergreen
Colour Dark green
Leaf shape / texture sagittate
  • Architectural foliage

Foliage interest: March–November

Seasonal Timeline

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Flowering
Foliage
Fruiting
Propagate
  • Flowering May Jun Jul
  • Foliage Mar Apr May Jun Jul Aug Sep Oct Nov
  • Fruiting Aug Sep
  • Propagate Mar Apr

How to propagate

One way to grow more Arum lily:

Division Mar Easy

You'll need: Spade or sharp knife

  1. Lift or expose the clump as growth starts
  2. Cut into sections, each with roots and healthy buds
  3. Replant at the same depth in improved soil
How long
1 hour
It's worked when
high
Then
Water in well and keep moist while new roots form.

Divide clumps in spring, leaving a bud on each piece; let cut surfaces dry a day before replanting.

Maintenance Calendar

  • Mar Divide congested clumps as growth starts
  • Apr Feed and top-dress with compost
  • Jul Remove faded spathes
  • Nov Mulch crowns in borders in cold areas

Garden Design

Works well in: Cottage, Tropical / Exotic

Pure white spathes over glossy arrow-shaped leaves, superb at a pond edge in up to 30 cm (12 in) of water, which also protects the crown from frost.

Companion planting: Ferns, Hostas, Irises, Primulas

Safety

  • Toxic to humans
  • Toxic to dogs
  • Toxic to cats
  • Toxic to horses
  • Skin irritant

All parts contain calcium oxalate and are harmful if eaten; sap irritates skin and eyes. A declared pest in Western Australia and an invasive weed of wetlands in Victoria, South Australia and New Zealand; check before planting.