Elephant ears, which primarily refer to the tropical plants in the genera Colocasia and Alocasia, are classified as tender perennials. Whether these plants function as a perennial or an annual is determined entirely by the climate where they are grown. In their native tropical and subtropical environments, they grow year-round. However, a lack of cold tolerance forces gardeners in many regions to treat them differently, dictating whether the plant survives winter in the ground or must be stored indoors.
Understanding the Tender Perennial Status
A tender perennial is a plant that has a life cycle extending beyond two years but cannot withstand cold temperatures or frost. Elephant ears thrive in warm conditions, and their foliage begins to suffer when temperatures dip below 50°F (10°C). The entire plant is typically killed by a hard freeze, preventing survival in many regions.
The USDA Plant Hardiness Zone system defines where these plants act as true perennials. Elephant ears are generally hardy in Zones 8, 9, 10, and 11, where temperatures rarely drop below freezing. Gardeners in Zones 7 and colder must lift the tubers in the fall to prevent freezing, effectively treating the plant as an annual that needs to be replanted each spring.
Seasonal Growing Requirements
Cultivation of elephant ears during the active growing season requires conditions that mimic their humid, tropical origin. They are heavy feeders and drinkers, demanding consistent moisture and nutrients to support rapid growth and expansive leaf size. The soil should be organically rich and uniformly moist, with many varieties of Colocasia even tolerating standing water.
Most elephant ear varieties perform best in full sun to partial shade. Cultivars with darker foliage benefit from more direct sunlight to intensify their color, but in extremely hot climates, afternoon shade helps prevent scorching. To support the production of massive leaves, a liquid, balanced fertilizer should be applied regularly, often every two to three weeks, throughout the spring and summer.
Regular watering is essential, as the soil should never be allowed to completely dry out. The plant’s large leaf surface area rapidly transpires moisture, necessitating frequent irrigation, especially for container plants. Providing a thick layer of mulch around the base helps retain moisture and keeps the root zone insulated.
Overwintering Techniques for Cold Climates
For gardeners in colder climates (generally Zone 7 and below), preserving elephant ears means digging up the underground corms or tubers and storing them indoors for dormancy. This process begins after the first light frost causes the foliage to collapse and die back naturally. Waiting until a light frost signals dormancy, but digging must occur before a hard freeze damages the root mass.
Once the foliage has been killed by frost, the stems should be trimmed back, leaving only about four to six inches of growth above the corm. The entire root mass is then dug out, taking care not to nick or damage the tuber with a shovel. Excess soil is gently brushed off, but washing the tuber with water should be avoided, as moisture encourages rot during storage.
The tubers must undergo a curing process to dry the exterior and prevent fungal issues. They should be placed in a warm, dry, and well-ventilated location out of direct sunlight for one to two weeks. This curing time prepares the corm for long-term dormancy by sealing any minor wounds.
After curing, the tubers are ready for storage in a dark, dry, and cool location. Ideal storage temperatures range from 40°F to 60°F (4°C to 16°C), which keeps the corms dormant without freezing. They are best packed in a breathable medium like dry peat moss, wood shavings, or coconut coir within a cardboard box or ventilated crate. The packing material should completely surround the tubers to insulate them and absorb residual moisture.
Throughout the winter, the stored tubers should be checked periodically for signs of rot or shriveling. If they appear too dry, a light misting of water can be applied sparingly to rehydrate them. In late winter or early spring, four to six weeks before the last expected frost, the stored tubers can be potted in fresh soil indoors to break dormancy and get a head start on the growing season.