Bulb · Araceae
Calla Lily
Zantedeschia aethiopica
Hand it rich, moist soil and a sunny spot, and the calla rewards you with tall, sculptural blooms.
Full sun
Every 2–4 days
USDA 8–10
2–3 ft · 0.6–1 m
Overview
Ever notice how clean a calla looks? It's just a single curled spathe wrapped around a slim golden spike, and that's the whole charm. Here's the funny part: it isn't a true lily at all. It belongs to the arum family, comes from southern Africa, and shows up everywhere as a cut flower and a star of summer beds. White's the classic, but the wider family also turns up in cream, yellow, and deep wine shades.
It grows from a chunky underground rhizome and keeps coming back year after year in mild spots. Now, here's where it breaks the rules: this one actually likes wet feet, which is the opposite of what most bulbs want. It'll happily sit in boggy ground or right at a pond edge, and it can stand in water up to about a foot deep without batting an eye. So during active growth? That nagging worry about overwatering pretty much goes away.
As pretty as it is, you've got to remember the whole plant is toxic to people and animals. Every part is loaded with sharp calcium oxalate crystals that burn the mouth the second they're bitten, so this is one to look at, not snack on. Just put it somewhere pets and little kids can't get at the leaves or the sap, and you're all set.
Care
The short version: full sun to part shade, soil that stays rich and reliably moist, a balanced feed through the growing months, and a rhizome divide every year or two once the clump gets crowded.
Light
Callas flower their best in full sun, but they'll take partial shade without much fuss, which really helps if your summers get scorching. The catch is simple: the more sun they get, the stronger and more upright the blooms.
Water
This is a plant that just wants to stay wet. Keep the soil consistently moist to boggy and water it every 2 to 4 days while it's growing, and whatever you do, don't let it dry out. It'll even sit in standing water up to about a foot deep, so leaning damp is totally fine.
Soil
Pop it into rich, humusy clay or loam that's full of organic matter. Unlike most bulbs, the calla doesn't mind poor drainage or the odd flood, and it's pretty easygoing about pH anywhere from 6.0 to 8.0.
Temperature
It handles a wide range, somewhere around 10°F to 86°F (-12°C to 30°C), though it's happiest in mild summer warmth. A hard freeze just pushes it into dormancy, so where winters get rough, you'll want to lift the rhizomes or pile on heavy mulch.
Humidity
Calla lilies like the air on the humid side, which makes sense for a plant that loves damp ground and pond edges. Dry air on its own won't do them in, though, as long as the soil stays moist.
Feeding
Feed it monthly through spring and summer while it's growing hard, and reach for a balanced general-purpose fertilizer. Once the leaves start fading and the plant heads toward rest, you can ease off.
Pruning
Snip off the spent flower stalks and any yellowing or dead leaves to keep things looking neat. When the foliage dies back for the season, just trim it down as the plant settles into dormancy.
Repotting
Plan to divide and repot every 1 to 2 years, or sooner if the clump's getting cramped. How do you know it's time? Rhizomes packing the pot, fewer flowers than usual, and roots poking out the drainage holes.
Size & spacing
A grown calla stands about 2 to 3 feet (61 to 99 cm) tall and spreads 12 to 24 inches (30 to 61 cm) wide. Set the rhizomes roughly 12 to 18 inches (30 to 46 cm) apart so each clump's got room to fill in.
When to plant
Callas don't get going until things warm up, so there's no rush. If your winters get cold, start the rhizomes indoors in late winter, then move them outside once the frost's gone. Flowers show up in early summer, and the best of the show runs through June and July.
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
Most calla trouble either starts down in the soil or shows up on the leaves. Rot from soggy ground is the one that can really hurt, while beetles and thrips are more annoying than dangerous. Find your symptom below and jump on it early.
Soft, mushy rhizome and collapsing leaves
If the rhizome's gone soft and mushy and the leaves are flopping over, that's rhizome rot, and it comes from soil that stays waterlogged and starved of air. Lift the rhizome and take a good look, because any brown, mushy, smelly tissue has to go. For a rhizome that's still worth saving, cut off the soft spots, let the cuts dry and heal, then replant it somewhere that drains better.
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
Leaves chewed down to lace and flowers all torn up? That's Japanese beetles at work, those metallic green-bronze bugs that swarm foliage and blooms all summer. Easiest fix is to pick them off by hand and drop them into a tub of soapy water. If a plant's really getting hammered, keep at it, since the more you grab early, the fewer show up to feed.
Fix:
- Handpick beetles into soapy water
- Reduce populations on heavily infested plants
Silvery, stippled patches on the leaves
See a silvery, speckled finish on the leaves, maybe with little black frass dots underneath? That's usually tiny banded greenhouse thrips rasping away at the surface. Strip off and bin the worst of the foliage to lighten the load. After that, just keep the plant well fed and watered, because a strong, vigorous calla shrugs off light thrips damage no problem.
Fix:
- Remove and dispose of heavily infested foliage
- Improve growing conditions to support plant vigor
Toxicity
Bottom line? Nobody should eat any of it, ever. Every part of a calla is packed with insoluble calcium oxalate crystals that drive sharp little needles into any mouth that bites down, and that means instant burning, drooling, and swelling. It's a no-go for cats, dogs, horses, livestock, rabbits, birds, and people, and even the sap can irritate bare skin, so wash your hands after handling and keep it well away from pets and kids.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that bites into any part feels the burn right away, so you'll see it pawing at its mouth, drooling a lot, and throwing up. The lips and tongue can puff up too, and swallowing starts to hurt.
Dogs Toxic
When a dog chews the leaves or sap, it'll drool hard and gag, often with a swollen, sore mouth. The good news is most back off fast once the crystals sting, so they rarely eat enough to do any lasting harm.
Horses Toxic
In a horse, the crystals scald the mouth and tongue, which brings on swelling, drooling, and a clear case of not wanting to eat. Horses can't vomit, so the trouble mostly shows up as a sore mouth and turning down feed.
Rabbits Toxic
That same calcium oxalate that bugs cats and dogs irritates a rabbit's mouth and gut just as much. So keep your callas, any cuttings, and dropped leaves well out of reach of any rabbit grazing nearby.
Livestock Toxic
Cattle, sheep, and goats that graze the foliage end up with mouth and throat irritation, drooling, and an upset gut. The harsh taste usually puts them off, but a hungry animal on thin pasture might risk it anyway.
Birds Toxic
Birds run into the very same irritating crystals in the leaves and sap, so a pecking parrot or chicken can wind up with a sore, swollen mouth. Honestly, it's best to keep the plant away from birds altogether.
People Caution
No part of a calla is safe to eat, and one bite brings instant burning of the lips, tongue, and throat plus drooling and swelling. Even the sap can leave skin itchy and raw, so wash up after handling and keep kids well clear.
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
Almost every calla you'll run into is a pick of the white arum lily, chosen for how big or what color the spathe is. These two are the ones you'll spot most.
White Giant
White Giant is the one grown for its oversized pure white spathes, and it's easily the showiest of the classic callas.
Green Goddess
Green Goddess opens white down at the base and washes into green near the tips, so every bloom ends up with a cool two-tone look.
How to propagate
Want more callas? They're easy to multiply, and splitting up a settled clump is by far the quickest way to get more flowering plants.
DivisionEasy
Early spring or late summer to early fall · One growing season
The easiest way to get more callas is to just split a crowded clump. Do it in early spring or in that cooler stretch from late summer into fall, lifting the rhizomes and pulling them apart with your hands. Each healthy piece settles right in and fills out over a single growing season.
SeedModerate
When ripe seed is available · Multiple seasons to flowering
Growing from seed? That takes patience. You can sow ripe seed whenever you manage to get it, but the seedlings will spend several seasons sizing up before they flower. If you just want more blooming plants without the wait, division's way faster.
Bulbs & cormsEasy
Spring · One growing season
Starting with bought rhizomes is the route most folks take, and it couldn't be simpler. Plant them in spring, 3 to 4 inches deep and 12 to 18 inches apart, and they'll put on growth and flower within their first season.
Myths
The calla lily is a true lily and causes fatal kidney failure in cats like Easter and tiger lilies do.
Easy mistake, but the calla isn't actually a true lily; it's in the arum family. So no, it doesn't cause the deadly kidney failure that real lilies trigger in cats. What it does carry is insoluble calcium oxalate crystals, which burn the mouth and bring on drooling and vomiting in cats and dogs. Painful? Sure. Life-threatening? Hardly ever.