Bulb · Araceae
Caladium
Caladium bicolor
Give it warm soil, dappled shade, and steady moisture, and caladium answers with heart-shaped leaves splashed in red, pink, and white.
Partial shade
Every 2–4 days
61–86°F · 16–30°C
60–90 days
Overview
Caladium earns its place for the leaves, not the flowers. Each tuber pushes up big, paper-thin, heart-shaped foliage marbled in red, pink, white, and green, the colors bleeding into one another across blades thin enough to glow when light passes through. A single plant carries real color into a shady corner where little else will, and it belongs to the arum family, the same group as philodendrons and peace lilies. Like its relatives, it leans toward warmth and humidity.
This is a tropical tuber that lives by warmth. It wakes, grows quickly, reaches full size in one season, then dies back and rests as the weather cools. You can grow it in a shaded bed, a patio pot, or indoors as a houseplant, but in every case it wants warm soil and air around 16°C and up before it stirs at all.
Color is the entire point here, and shade protects it. Strong sun bleaches the markings back toward plain green and scorches the delicate leaves, while dappled light keeps the reds and pinks deep and the patterning crisp. The plant is not difficult once the warmth is there, but it stays particular about that one thing.
Care
The short version: give caladium partial to dappled shade, warm soil that never drops cold, and even moisture right through the growing season. Add light feeding and high humidity, then taper the water back as the leaves yellow and fold into dormancy.
Light
Partial to dappled shade is the sweet spot, roughly 2 to 4 hours of gentle sun with shelter from the hot afternoon light. Too much direct sun fades the bright markings to green and scorches the thin leaves, while deep shade keeps the color at its richest.
Water
Caladiums drink heavily in active growth. Keep the soil evenly moist to the touch but never waterlogged, since soggy ground rots the tubers from below. Watering every 2 to 4 days suits most plants, and you should ease off as the leaves yellow and head into dormancy.
Soil
Fertile, well-drained soil loaded with organic matter holds moisture without staying wet, which is exactly what the tubers want. Aim for a slightly acidic pH of 5.5 to 6.0, and lean on good drainage to keep tuber rot at bay.
Temperature
Warmth matters most of all. Caladiums grow between 61°F and 86°F (16°C to 30°C) and stall in anything cooler, so let the soil warm through before the tubers go out.
Humidity
These are tropical plants that want humidity of 60% or more. Dry indoor air leaves the leaf edges crisp and brown, so group plants together, use a pebble tray, or run a humidifier in a dry room.
Feeding
Feed every two weeks through the growing season with a balanced liquid fertilizer, or use a slow-release low-phosphorus formula instead. Go easy, since over-feeding fades the reds and whites back toward green.
Pruning
There is little to prune. Take off yellowing or damaged leaves at the base, and removing the central bud on a tuber before planting pushes out more shoots and leaves.
Repotting
Caladiums are replanted each year from stored tubers rather than potted on. Leave established clumps undisturbed, and lift and divide only when the tubers crowd and lift at the surface or the leaves shrink over the season.
Size & spacing
A caladium grows 12 to 30 inches (30 to 76 cm) tall with a matching spread. Set the tubers 8 to 12 inches apart so the broad leaves have room to fill in.
When to plant
Caladiums run on warmth, not on the calendar. You can start the tubers indoors a few weeks ahead of the last frost for a head start, but they go out only once the soil has warmed in late spring. From there they fill out across summer and die back as the season cools.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Start tubers indoors 4-6 weeks before the last frost in a warm spot, keeping the medium about 70 degrees F, to get a head start in cold-winter regions
- Plant: After all danger of frost has passed and soil reaches at least 60-70 degrees F (late spring to early summer)
- Harvest: Grown for foliage, which reaches full size in one season; insignificant arum-type spathe flowers may appear in summer
Hardiness
USDA hardiness zones: 9–10
Temperature: down to -7°C
Troubleshooting
Caladium trouble tends to show up in two places: tubers that fail to wake in cold ground, and leaves that lose their color or get chewed. The early signs are easy to read, and most of it is easy to head off before it spreads.
Cold ground stalls or rots the tubers
Cold, wet soil is almost always why tubers stall or rot before they push a single shoot through the surface. Hold off until the ground sits steady at 60°F to 70°F (16°C to 21°C), then loosen it for drainage so the soil stays moist without turning soggy. Squeeze each tuber and toss any that feels soft or mushy; clean, disease-free stock is what keeps fungal tuber rot out of the bed.
Fix:
- Wait to plant until soil is consistently 60-70 degrees F
- Improve drainage and reduce watering so soil is moist but not saturated
- Discard soft or rotted tubers and start with disease-free stock
The bright markings wash out toward plain green
When the red, pink, and white splashes drain away and the leaves green over, the culprit is usually too much direct sun or a heavy hand with the fertilizer. Shift the plant into partial or dappled shade, out of the hot afternoon glare, and feed only a light touch once or twice across the season. Shade keeps the color rich and the markings sharp against the leaf.
Fix:
- Move to partial or dappled shade with protection from hot afternoon sun
- Reduce fertilizer to a light application once or twice in the season
Chewed edges and shiny slime trails on the leaves
Ragged holes punched through the blades and bitten-away margins are usually the work of slugs and snails, which feed after dark and leave glistening slime trails across the foliage. Hand-pick them at night or lay out bait, and clear away the damp hiding places they shelter in. Leaves that look torn rather than neatly chewed point instead to wind or hail battering the brittle foliage, so a sheltered spot helps.
Fix:
- Hand-pick slugs and snails or use baits per label
- Site out of strong wind to protect brittle leaves
Toxicity
Every part of a caladium is toxic, with no exception. The leaves, stems, and tubers hold insoluble calcium oxalate crystals that act like microscopic needles, and a single bite causes intense burning, drooling, and swelling of the mouth and throat. No part is edible, so keep the plant and any stored tubers away from pets, livestock, and children.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Toxic
A cat that bites into a leaf feels the burn the instant it does, pawing at its mouth and drooling hard. The lips, tongue, and throat begin to swell, and vomiting and trouble swallowing often follow close behind.
Dogs Toxic
A dog that chews any part of the plant gets a sharp sting through the mouth, with heavy drooling and a tongue that swells up. Most back away quickly, but vomiting and a refusal to eat can linger for a day.
Horses Toxic
The crystals inflame a horse's mouth and lips the moment they make contact, bringing pain, drooling, and difficulty swallowing. Horses cannot vomit, so the irritation stays right where the plant was bitten.
Rabbits Toxic
Rabbits run into the same needle-like crystals, which scald the mouth and gut and put them off their food. Keep the plant and any stored tubers well out of their reach.
Livestock Toxic
Grazing animals such as goats, sheep, and cattle pick up mouth and gut irritation if they sample the foliage. Most spit it out fast because the burn is immediate, but keep the plants well away from pasture.
Birds Toxic
The oxalate raphides irritate a bird's mouth and crop just as they do in mammals, so pet birds should never get near the leaves or sap.
People Caution
No part is edible; a single bite brings instant burning of the lips and mouth, drooling, and swelling, and the sap can leave skin itchy. Wash your hands after handling and keep it away from children.
Keep plants and stored tubers out of reach of pets and children; wash hands after handling sap.
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
Caladiums come in hundreds of named selections, sorted mainly by leaf shape. A few stand out as worth knowing by name.
Candidum
A classic fancy-leaved selection prized for its near-white leaves, each blade laced through with bold green veins.
Pink Cloud
A named fancy-leaved cultivar listed by NC State, carrying soft, pink-flushed foliage across its heart-shaped leaves.
Lance-leaved (strap-leaved) types
Narrower, strap-like leaves that generally stay under 12 inches tall and take more sun than the broad fancy-leaved kinds.
How to propagate
Caladiums multiply through their tubers, either by cutting a tuber into pieces or by splitting off the offsets a clump makes on its own.
DivisionEasy
Late winter to early spring before planting, while tubers are dormant · 4-6 weeks to sprout in warm soil; full size in one season
Divide the tubers in late winter or early spring while they sit dormant. Cut a large tuber into pieces, making sure each one carries at least one eye, then let the cut faces dry and callus over. Set them eye-side up about 2 inches deep; in warm soil the pieces sprout in 4 to 6 weeks and fill out to full size within the single season.
Offsets & pupsEasy
At lifting in autumn or replanting in spring · One growing season to reach mature size
Caladiums build their own daughter tubers in a cluster around the parent. Lift the clump in autumn, or at replanting in spring, snap the offsets free, and plant them on their own, where they take a single growing season to reach mature size.
Myths
Caladiums need full sun to bring out the bright colors in their leaves.
The opposite is true; color comes in deepest under partial or dappled shade, while too much direct sun fades the reds, pinks, and whites toward green and scorches the fragile leaves.
Caladium tubers can go in the ground in early spring, the same as other hardy bulbs.
Caladiums are tropical and will rot or stall in cool ground. Wait until the soil reaches at least 60°F to 70°F (16°C to 21°C) before the tubers go in, which usually means late spring rather than the first warm day.