Bulb · Araceae
Calla Lily
Zantedeschia aethiopica
Set it in rich, moist ground and good light, and the calla brings tall, sculptural blooms to a space.
Full sun
Every 2–4 days
USDA 8–10
2–3 ft · 0.6–1 m
Overview
Among cut flowers, the calla reads as quiet sophistication, the kind of single sculptural stem that finishes a room without trying. It is not a true lily but a member of the arum family, brought from southern Africa and prized worldwide for its place in arrangements and bold summer plantings. The pure white form anchors the most timeless schemes, while cream, yellow, and deep wine relatives give a palette to play with across a home.
Rising from a substantial underground rhizome, it settles in as a returning fixture in mild-climate gardens. What makes it such an obliging plant for considered, low-effort spaces is its love of water: it belongs at a pond edge or in damp, shaded ground that defeats fussier bulbs, and it stands in water up to about a foot deep without protest. For a courtyard, a water feature, or a border that stays moist, it asks very little of a busy routine.
For all its poise, the calla earns one firm rule of placement, because the whole plant is toxic to people and animals. Every part carries sharp calcium oxalate crystals that sting the mouth on contact, so this is a flower meant for the vase and the view, never the table. In a home with pets or small children, give it a high shelf, a contained bed, or a spot well out of reach, and its elegance comes with no compromise.
Care
The short version: site it in full sun to part shade, keep the soil rich and reliably moist, work in a balanced feed through the growing months, and lift and divide the rhizomes every year or two as the clump fills its space.
Light
The calla performs best in full sun, where its stems stand tallest, yet it accepts partial shade, a welcome trait for a shaded courtyard or a spot that bakes through high summer. The brighter the position, the stronger and more upright the blooms that finish the scene.
Water
This is a plant for the moist corner of a garden. Keep the soil consistently moist to boggy and water every 2 to 4 days through active growth, never letting it dry. It will hold its own in standing water up to about a foot deep, which makes it a natural at a water feature or a low, damp border.
Soil
Give it rich, humusy clay or loam worked full of organic matter, the kind of ground that keeps a moist bed thriving. Unlike most bulbs it shrugs off poor drainage and the occasional flood, and it settles happily across a pH band from 6.0 to 8.0.
Temperature
It lives comfortably across roughly 10°F to 86°F (-12°C to 30°C), though mild summer warmth shows it at its most graceful. A hard freeze simply sends it into dormancy, so in cold-winter regions the rhizomes want lifting or a generous mulch to carry them through.
Humidity
Air on the humid side suits the calla and its taste for damp ground and water's edge. Dry air alone will not undo it, provided the soil beneath stays moist and the planting keeps its footing.
Feeding
Work in a balanced general-purpose fertilizer monthly through spring and summer while growth is in full swing. As the foliage softens and the plant eases toward dormancy, let the feeding wind down with the season.
Pruning
Clip away spent flower stalks and any tired, yellowing leaves to keep the planting looking composed. Once the foliage dies back for the year, cut it down as the plant slips into its winter rest.
Repotting
Divide and repot every 1 to 2 years, or sooner once a clump outgrows its place. Rhizomes crowding the container, a thinner show of flowers, and roots edging from the drainage holes are the quiet signals that it is time to refresh the arrangement.
Size & spacing
A mature calla stands 2 to 3 feet (61 to 99 cm) tall and spreads 12 to 24 inches (30 to 61 cm) wide, an easy scale for a border or a generous pot. Set the rhizomes about 12 to 18 inches (30 to 46 cm) apart so each clump has the room to read well.
When to plant
The calla follows the season's mood, waking only as warmth returns. Where winters turn cold, start the rhizomes indoors in late winter, then settle them outside once frost has passed. The reward lands in early summer, when the display comes into its own through June and July and dresses a garden at its most generous.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Start rhizomes indoors in late winter to early spring in cold-winter areas.
- Plant: Plant rhizomes outdoors in spring after frost, 3-4 inches deep and 12-18 inches apart.
- Harvest: Blooms June to July.
Hardiness
USDA hardiness zones: 8–10
Temperature: down to -12°C
Troubleshooting
A calla's troubles tend to surface either underground or across its foliage, and most are easily managed once spotted. Rot in waterlogged ground is the one worth real attention, while beetles and thrips read more as a passing blemish than a threat. Match the look below to its cause and respond early to keep the planting looking its best.
Soft, mushy rhizome and collapsing leaves
When a rhizome turns soft and the foliage caves in, the culprit is rhizome rot, the result of soil left waterlogged and short of air. Lift the rhizome to assess it, and let any brown, foul-smelling tissue go. On a rhizome still worth keeping, pare away the soft spots, allow the cuts to cure, then return it to better-drained ground and the planting can recover its form.
Fix:
- Lift affected rhizomes and discard rotted ones
- Cut away soft tissue from salvageable rhizomes and let cure
- Replant healthy rhizomes in better-drained, aerated soil
Leaves chewed to lace and flowers torn up
Foliage chewed to lace and blooms left ragged is the signature of Japanese beetles, metallic green-bronze insects that gather on leaves and flowers across summer. Pick them off by hand into a tub of soapy water to keep the display intact. On a planting that is taking a beating, stay with it, since clearing them early means far fewer arrive to feed.
Fix:
- Handpick beetles into soapy water
- Reduce populations on heavily infested plants
Silvery, stippled patches on the leaves
A silvered, speckled cast over the leaves, often with black frass dotted beneath, points to banded greenhouse thrips working the surface. Remove and discard the worst-affected foliage to tidy the look. Then keep the planting well fed and watered, because a vigorous calla carries light thrips damage without losing its presence.
Fix:
- Remove and dispose of heavily infested foliage
- Improve growing conditions to support plant vigor
Toxicity
Treat the calla as strictly decorative, never edible. Every part holds insoluble calcium oxalate crystals that press sharp needles into any mouth that bites them, bringing instant burning, drooling, and swelling. The caution covers cats, dogs, horses, livestock, rabbits, birds, and people alike, and the sap can irritate bare skin, so wash hands after arranging or planting and choose a setting well clear of pets and children.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that bites any part feels the burn at once, pawing at its mouth, drooling heavily, and vomiting. The lips and tongue can swell and swallowing turns painful, so place the plant somewhere a cat simply cannot reach.
Dogs Toxic
A dog that chews the leaves or sap drools hard and gags, often with a swollen, sore mouth. Most back off quickly once the crystals sting, so they rarely eat enough to come to lasting harm, but a high or contained spot spares the trouble.
Horses Toxic
In a horse, the crystals scald the mouth and tongue, bringing swelling, drooling, and a clear reluctance to eat. Horses cannot vomit, so the discomfort shows mainly as a sore mouth and a refusal of feed.
Rabbits Toxic
The same calcium oxalate that troubles cats and dogs irritates a rabbit's mouth and gut. Keep callas, cuttings, and dropped leaves well out of reach of any rabbit grazing nearby.
Livestock Toxic
Cattle, sheep, and goats that graze the foliage get mouth and throat irritation, drooling, and an upset gut. The acrid taste usually deters them, though hungry animals on thin pasture may take the risk.
Birds Toxic
The leaves and sap carry the same irritating crystals for birds, so a pecking parrot or chicken can end up with a sore, swollen mouth. Keeping the plant away from birds entirely is the safe choice for an aviary household.
People Caution
No part of a calla is edible, and a bite brings instant burning of the lips, tongue, and throat along with drooling and swelling. The sap alone can leave skin itchy and raw, so wash up after handling and keep children well clear of the planting.
Keep plant, cut flowers, and sap away from pets and children; wash hands after handling as the sap can cause skin and mouth irritation.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Nearly every calla offered for the garden is a selection of the white arum lily, chosen for the scale or shade of the spathe to suit a scheme. These two appear most often.
White Giant
White Giant is grown for its oversized pure white spathes, the most striking presence among the classic callas and a natural for a statement planting.
Green Goddess
Green Goddess opens white at the base and shades to green toward the tips, lending each bloom a two-tone character that suits an understated palette.
How to propagate
Callas are generous to expand, and dividing a settled clump is the simplest way to carry a favorite planting through a home and garden.
DivisionEasy
Early spring or late summer to early fall · One growing season
The simplest way to extend a favorite planting is to divide a crowded clump. Take it on in early spring or in the cooler stretch from late summer into fall, lifting the rhizomes and easing them apart by hand. Each healthy piece settles in and fills out across a single growing season, ready to anchor a new corner.
SeedModerate
When ripe seed is available · Multiple seasons to flowering
Seed is the patient route. Sow ripe seed when it comes your way, but expect the seedlings to spend several seasons sizing up before they flower. For more blooming plants to dress a space without the wait, division is by far the quicker path.
Bulbs & cormsEasy
Spring · One growing season
Bought rhizomes are the usual and most dependable start. Plant them in spring, 3 to 4 inches deep and 12 to 18 inches apart, and they put on growth and flower within their first season, settling neatly into a new scheme.
Myths
The calla lily is a true lily and causes fatal kidney failure in cats like Easter and tiger lilies do.
The name invites the mistake, but the calla is no true lily; it sits within the arum family. It does not bring on the deadly kidney failure that genuine lilies cause in cats. Its concern is instead a load of insoluble calcium oxalate crystals, which burn the mouth and prompt drooling and vomiting in cats and dogs, uncomfortable but rarely life-threatening.