Caladiums, often known as “Angel Wings” or “Elephant Ear,” are tropical foliage plants prized for their vibrant, heart-shaped leaves. Native to Central and South America, successful cultivation hinges entirely on correct planting timing. Planting at the right moment ensures the tubers break dormancy quickly and develop into full, colorful displays, as they are highly intolerant of cold temperatures.
Essential Temperature Requirements
The most significant factor determining the correct planting time is the ambient temperature, particularly the temperature of the soil. Caladium tubers require a consistently warm environment to emerge from dormancy and begin active growth. Planting them in cool soil will cause slow growth, or worse, the tubers may rot before they can sprout.
The soil temperature is the primary trigger for growth and should be a minimum of 65°F for several consecutive days. For optimal results and rapid sprouting, the soil should ideally reach 70°F or higher. Air temperatures also play a role, needing to be consistently above 60°F, especially at night. Gardeners must wait until all danger of frost has passed, as a single cold snap can destroy the sensitive tubers.
Outdoor Planting Timelines by Region
The best time to plant caladiums outdoors varies based on your geographic location and the average last frost date. In regions where caladiums are perennial (USDA Hardiness Zones 9 and 10), planting can occur much earlier. Gardeners in these areas can plant bare tubers as early as March 15th, or whenever the soil has consistently warmed up. The planting window in South Florida, for instance, extends from March through September, allowing for a long season of growth.
In areas where caladiums are grown as annuals, typically Zones 8 and colder, a more cautious approach to timing is necessary. For Zone 8, planting usually begins around April 15th, provided the soil minimums are met. Moving into the mid-range climates like Zone 7, the recommended outdoor planting time shifts to around May 1st, or after the threat of frost is long gone.
Gardeners in the cooler northern climates, including Zones 3 through 6, must wait the longest for warm weather. In these regions, planting should be delayed until late May or even mid-June, waiting for the soil to reach that required 70°F mark. In these cooler zones, the growing season is short, so pre-sprouting tubers indoors is often the best strategy to maximize the display period.
Starting Caladiums Indoors
Starting caladium tubers indoors provides a significant head start for gardeners in northern climates with shorter summers. This process, sometimes called “forcing,” encourages the tubers to break dormancy before outdoor conditions are suitable. The ideal time to start is four to six weeks before the expected safe outdoor planting date.
The tubers should be planted in a shallow tray or pot filled with a light, barely moist growing mix, such as a peat moss blend. Maintaining a warm environment is paramount, with temperatures kept consistently between 70°F and 75°F. Providing bottom heat via a specialized heating mat can accelerate the sprouting process, which otherwise takes four to eight weeks. Once the plants have developed leaves and the outdoor soil has stabilized above 65°F, they can be safely transitioned outside.
Planting Technique
Once the optimal planting time has arrived, proper technique ensures the tubers establish quickly and thrive. Begin by preparing the planting site with rich, well-draining soil, amending heavy soil with organic material like compost to improve drainage. Caladium tubers are planted shallowly, typically just 1.5 to 2 inches beneath the soil surface.
Correct orientation of the tuber is important for the fastest sprouting time. The knobby, often puckered side of the tuber, which contains the dormant growth points or “eyes,” should be placed facing upward. Tubers should be spaced between 8 to 12 inches apart to allow for the full, mature spread of the foliage. After planting, water the area generously to settle the soil and initiate the growth process.