Caladium

A tropical foliage plant with large, heart-shaped leaves in spectacular combinations of red, pink, white, and green. Caladiums thrive in warm shade with consistent moisture and add dramatic color to areas where flowers struggle. Dig tubers before frost in cold climates and store them in a warm, dry place over winter.

Caladiums are propagated exclusively from tubers rather than seeds. Start tubers indoors four to six weeks before the last frost in warm, moist potting mix at 70 to 80 degrees Fahrenheit. Plant with the knobby eyes facing upward, two inches deep. To increase the number of plants, large tubers can be divided by cutting between the eyes, dusting cut surfaces with fungicide, and allowing them to dry before planting. Each division should have at least one eye to sprout successfully.

Plant caladium tubers indoors four to six weeks before the last frost date or directly outdoors once soil temperatures reach 70 degrees Fahrenheit. Set tubers two inches deep with the knobby side facing up in warm, moist potting mix. Maintain soil temperature above 70 degrees for best sprouting, which takes two to four weeks. Pre-starting indoors gives plants a significant head start in short-season areas.

Transplant or direct-plant outdoors in a shaded location with rich, consistently moist soil. Space tubers eight to twelve inches apart depending on variety size. Caladiums are tropical plants that demand warmth and humidity, performing poorly when temperatures drop below 65 degrees Fahrenheit. Apply two to three inches of mulch to maintain soil moisture and moderate temperature fluctuations.

Water regularly to keep soil evenly moist but never waterlogged. Feed every two to three weeks with a balanced liquid fertilizer during active growth. As fall approaches and leaves begin to yellow naturally, reduce watering gradually. In zones 8 and below, dig tubers after the first light frost blackens the foliage, cure them for a few days, and store in dry peat moss at 55 to 60 degrees Fahrenheit over winter.

Caladiums pair naturally with other shade-loving tropicals including coleus, begonias, impatiens, and ferns. Their bold leaf patterns create dramatic contrast with the fine textures of maidenhair ferns and astilbe foliage. Plant with hostas for a lush tropical effect in shaded borders. In containers, combine with trailing sweet potato vine and upright elephant ears for a stunning tropical display.

Caladiums require rich, humus-heavy soil with excellent moisture retention and good drainage. Amend planting areas with generous amounts of compost, leaf mold, or peat moss. A slightly acidic pH of 5.5 to 6.5 is ideal. Feed every two to three weeks during active growth with a balanced liquid fertilizer. Avoid fertilizers high in nitrogen, which can reduce the intensity of leaf coloration. Stop feeding in early fall as plants begin their natural dormancy.

Ideal Temperature

Hardiness Zone Compatibility

Caladium leaves can be cut for indoor arrangements throughout the growing season. Cut stems at the base of the plant with a sharp, clean knife. Immediately place stems in warm water as the sap can irritate skin, so wear gloves when handling. Individual leaves last five to seven days in a vase. In fall, allow foliage to die back naturally before digging tubers for winter storage.

Storage & Preservation

After the first light frost kills the foliage, dig caladium tubers carefully with a garden fork. Brush off excess soil and cure tubers in a warm, dry location for several days. Store in dry peat moss, vermiculite, or paper bags at 55 to 60 degrees Fahrenheit in a dark location. Check stored tubers monthly and discard any showing signs of rot. Caladium leaves can be pressed between parchment paper for botanical crafts, though colors will fade over time.

Troubleshooting Common Problems

The most frequent issue is failure to sprout, usually caused by planting in cold soil below 65 degrees Fahrenheit or planting tubers upside down. Scorched leaf edges indicate too much sun or inconsistent watering. Tubers stored too cold over winter may fail to grow the following season. Small leaves often result from planting tubers too deep or in soil lacking organic matter. All parts are toxic if ingested, so keep away from children and pets.

Growing Tips

1. Always wait until soil temperatures reach at least 21°C (70°F) before planting tubers outdoors. Planting in cold soil causes tuber rot and poor emergence. Use a soil thermometer to verify temperature at planting depth.
2. Plant tubers with the knobby side (growth eyes) facing up, about 5 cm deep and 20-30 cm apart. The smooth rounded bottom faces down. If you cannot tell which side is up, plant the tuber on its side and the shoots will find their way to the surface.
3. For bushier plants with more but smaller leaves, remove the large central bud from each tuber before planting by scooping it out with a clean knife. This forces the smaller secondary buds to grow, producing a fuller display.
4. Caladiums perform best in filtered light or dappled shade. Most fancy-leaf varieties scorch in direct sun, though newer sun-tolerant cultivars like the 'Florida Sun' series and strap-leaf types handle 4-6 hours of morning sun.
5. Maintain consistently moist but never waterlogged soil throughout the growing season. Caladiums wilt dramatically when dry but recover quickly after watering. Mulch heavily to conserve moisture and keep roots cool.
6. Feed every two weeks during active growth with a balanced liquid fertilizer (such as 20-20-20) diluted to half strength. Avoid high-nitrogen formulas that promote green pigment at the expense of the colorful reds, pinks, and whites.
7. Remove flower spathes as soon as they appear by snipping them at the base. Caladium flowers are insignificant compared to the foliage, and allowing them to develop diverts energy away from leaf production and tuber growth.
8. In zones colder than 9, dig tubers after the first light frost blackens the foliage. Cure them in a warm dry area for 5-7 days, then store in dry peat moss, vermiculite, or wood shavings at 15-18°C (60-65°F) until spring.
9. When growing caladiums indoors as houseplants, provide bright indirect light, temperatures above 18°C, and humidity above 50%. Group pots together or place on a pebble tray with water to boost ambient humidity around the foliage.
10. Always wear gloves when handling caladium tubers and foliage, as the calcium oxalate crystals in the sap can cause skin irritation, redness, and itching. Wash hands thoroughly after any contact and keep plants away from children and pets.