Elephant Ear plants (Colocasia and Alocasia species) bring a tropical feel to temperate gardens. These plants originate in warm climates and grow from underground storage structures, such as tubers or corms. Because these structures are highly susceptible to damage from freezing temperatures, gardeners in cold winter regions must implement a strategy to protect them, known as winterization. This process ensures the plant’s survival and return in the following growing season.
Timing the Winterizing Process
The winterization process begins with the initial drop in autumn temperatures. Gardeners should wait until after the first light frost (temperatures slightly below 32°F) causes the foliage to wilt or turn yellow. This light frost is beneficial because it cues the plant to draw nutrients from its leaves down into the underground tuber, initiating dormancy.
The window for action closes quickly, as a hard freeze can permanently damage the tubers. A hard freeze is defined as temperatures dropping significantly below freezing for several hours, penetrating the soil deeply enough to injure the storage structures. Once the leaves have naturally died back, it is time to either insulate or lift the plant before a sustained cold snap arrives.
Preparing Elephant Ears for Storage
Regardless of the chosen winterization method, the above-ground foliage must be managed first. After the leaves are killed by the light frost, the stems should be trimmed back significantly. Leaving a stalk of about 6 to 12 inches above the soil line is common practice; this remaining stem acts as a handle for digging and helps prevent moisture from entering the cut surface.
If the tubers will be dug up for indoor storage, allow the surrounding soil to dry slightly. Dry soil makes excavation cleaner and reduces moisture clinging to the tuber, minimizing the chance of rot during storage.
In-Ground Protection for Mild Climates
In warmer regions (generally USDA Hardiness Zone 8 and above), where the ground does not freeze solid, the tubers can often remain in place. The objective in these mild climates is to provide a thick layer of insulation directly over the plant’s root zone. This material prevents the shallow soil from undergoing damaging freeze-thaw cycles.
Apply a layer of organic material, such as straw, shredded leaves, or wood chips, to a depth of at least 8 to 12 inches over the cut-back plant. This covering traps residual soil heat and buffers the tuber from sudden temperature drops. Ensure the area remains well-drained throughout the winter, as excessive moisture combined with cold temperatures can cause the dormant tuber to rot.
Storing Tubers for Cold Climates
Gardeners in colder regions (typically Zone 7 and lower) must physically remove the tubers from the ground to protect them from a killing freeze. Begin by carefully lifting the tuber using a garden fork, starting the excavation a safe distance away from the plant’s base. This avoids accidental puncture or slicing of the storage structure. Any damage to the tuber’s outer skin can create an entry point for fungal pathogens that cause rot during dormancy.
Once lifted, the tubers need a period of curing or drying before being placed into long-term storage. This involves allowing the tubers to air-dry in a protected, well-ventilated location for approximately seven to ten days. The ideal temperature for this curing phase is warm, often between 60°F and 70°F, which encourages the outer skin to harden and seal any minor wounds.
After curing, excess soil and small roots can be gently removed, but the tuber should not be washed, as this can introduce too much moisture. The final step is to pack the dormant tubers in a cool, dark, and dry environment that maintains a consistent temperature range, preferably between 40°F and 55°F. They should be nestled in a breathable medium such as dry peat moss, vermiculite, or shredded newspaper, ensuring the tubers do not touch each other to prevent the spread of decay. Check the packed tubers periodically throughout the winter for signs of shriveling or soft spots indicating rot, allowing for the timely removal of compromised material.