When to Plant Caladiums: Soil Temperature, Depth and Storing Tubers

Caladiums (Caladium × hortulanum, also listed as C. bicolor) are aroids from tropical Central and South America, grown for their painted leaves in white, pink, red and green (Clemson, UF/IFAS). They grow from tubers and reach full size in one season (Clemson). Clemson describes two main types: fancy-leaf caladiums with big heart-shaped leaves, 12 to 30 inches tall, and lance-leaf (strap-leaf) types, usually under 12 inches with more, narrower leaves. Clemson rates them hardy only in zone 9 or 10, so most gardeners grow them as summer annuals or dig the tubers each fall.

When to plant caladiums by region

Our planting calendar shows your average last spring frost. Count back 4 to 6 weeks for an indoor start. Outdoors, caladiums go in later than most summer flowers, alongside okra and sweet potatoes (GardenPal note based on Clemson's okra rule).

How deep and far apart to plant caladiums

De-eyeing tubers for fuller plants

Each tuber has a large central bud surrounded by smaller ones. Clemson says that if the central bud grows alone, most varieties make only a few leaves, so it lifts out the big bud with the tip of a sharp knife, taking care not to damage the small buds around it. The tuber then sends up more shoots and leaves. Large tubers have more leaf buds and make fuller displays (Clemson). This step is optional (GardenPal note).

Watering, feeding and shade

• Water often. Keep the soil evenly moist but not soggy (Clemson, UF/IFAS); NC State calls caladiums water guzzlers. In beds, Iowa State waters weekly in dry weather and mulches about 2 inches deep.
• Feed lightly. UF/IFAS says too much fertilizer turns the leaves greener and dulls the reds and whites, and recommends a low-phosphorus, slow-release fertilizer. Clemson also warns against high-phosphorus fertilizer and feeds pots every two weeks with a liquid fertilizer; Iowa State feeds pots every 2 to 4 weeks.
• Keep fertilizer off the leaves, which can scorch them (Clemson, UF/IFAS).
• Sun: leaf colors are brighter in shade (UF/IFAS). Some newer cultivars handle more sun, so check the label (Clemson, UF/IFAS).
• Flowers: Clemson removes the small spathe flowers so the plant puts its energy into leaves.

Caladiums in containers

Clemson uses caladiums in hanging baskets, window boxes and patio planters. Use a pot with a drainage hole, because Clemson says caladiums rot if kept too wet, and check pots often, watering when the mix begins to dry (Iowa State). Potted caladiums are also an easy way to start early indoors and move outside once nights are warm (GardenPal note).

Digging and storing tubers

• When: in fall, before the leaves have lost all their color (Clemson). UF/IFAS gradually waters less as the leaves yellow.
• Dry: spread the tubers out for one to two weeks (Clemson), or about 10 days in semi-shade (UF/IFAS FPS83). Remove dry leaves and soil.
• Pack in dry peat moss, perlite or vermiculite, with the tubers not touching (Clemson).
• Store warm: no colder than 50°F (Clemson), and never in the refrigerator. UF/IFAS Gardening Solutions stores them at 60°F or above.
• Mild areas: tubers can stay in the ground in zones 8b to 11, though they often do better when dug and kept out of wet winter soil (UF/IFAS FPS83).
• Fresh tubers: Clemson notes second-year foliage is usually not as good as the first year, so many gardeners buy new tubers.

Rot, slugs and pet safety

Tuber rot, a fungal decay, is the main problem, in storage or in cold, wet soil (Clemson, UF/IFAS). Clemson advises planting disease-free tubers and storing them warm and dry. Clemson lists leaf spot on lower leaves, and NC State and UF/IFAS mention slugs and snails, though pests are not usually serious. For safety, the ASPCA lists caladium as toxic to dogs, cats and horses because of insoluble calcium oxalates, which cause mouth pain and swelling, drooling and vomiting. UF/IFAS advises supervising children and pets around caladiums, and NC State notes the sap can irritate skin. Wear gloves when handling tubers (GardenPal suggestion), and call a doctor, poison control or a veterinarian if any is eaten.

Caladiums near the vegetable garden

Most vegetables need full sun, so caladiums belong in the shady corners nearby: under trees, along a north wall or in pots on a shaded patio (GardenPal suggestion based on UF/IFAS light needs). Clemson pairs white caladiums with ferns, hostas and Lenten roses to brighten shade. For sunny summer bulbs, see when to plant cannas and when to plant calla lilies.

Frequently asked questions

When should I plant caladium bulbs?

Once the soil is about 70°F, around when okra is sown (Clemson). Up north, start them in pots 4 to 6 weeks before your last frost (Iowa State).

How deep do you plant caladium tubers?

1½ to 2 inches deep (Clemson), with the knobby eye side up (UF/IFAS).

How far apart should caladiums be planted?

8 to 12 inches apart (UF/IFAS); Clemson allows 8 to 14 inches.

Can caladiums take full sun?

Most do best with only 2 to 4 hours of direct sun, ideally in the morning (UF/IFAS). Some newer cultivars tolerate more sun.

Do caladiums come back every year?

Only in warm zones, about 8b to 11 (UF/IFAS FPS83). Elsewhere, dig the tubers in fall and store them dry above 50°F (Clemson).

Are caladiums poisonous to pets?

Yes. The ASPCA lists caladium as toxic to dogs, cats and horses because of calcium oxalate crystals. Call a veterinarian if a pet chews one.