Alocasia plants are tropical perennials known for their large, striking foliage, but they cannot tolerate freezing temperatures. To survive cold conditions, the plant enters dormancy, during which the foliage dies back and energy is stored in a thickened underground stem called a corm. Active storage of these corms is the most reliable strategy when ambient temperatures fall below approximately 55°F (13°C). By lifting and storing the corm in a controlled environment, the grower prevents the plant from rotting in cold, excessively damp soil, allowing the energy-rich storage organ to rest safely until the return of the growing season.
Preparing Corms for Dormancy
The process of preparing an Alocasia corm for storage begins only after the plant’s natural cues signal the onset of dormancy, typically when the foliage yellows and dies back following cooler temperatures or reduced daylight. Once the growing season has ended, carefully lift the entire root ball from the pot or ground, taking care not to damage the underground structures. Trim away old roots and any remaining dead leaves, leaving only the firm, main corm and any attached offsets.
The corm must be gently cleaned to remove excess soil without aggressive washing, which can introduce moisture and increase the risk of fungal issues during storage. The most crucial step is curing, which involves allowing the corms to dry and form a protective layer over any small cuts or abrasions. Curing should take place over one to two weeks in a shaded, well-ventilated location with stable, moderate temperatures. This allows the outer skin to completely dry and harden, acting as a barrier against pathogens and preventing rot.
Selecting the Ideal Storage Environment
Successful winter storage requires maintaining a specific, controlled environment that keeps the corm dormant without allowing it to desiccate or decay. The ideal storage temperature is cool and stable, remaining consistently above freezing but not warm enough to encourage premature sprouting, with a target range of approximately 45–60°F (7–15°C). Locations like an unheated basement, a cool closet, or a root cellar often provide this stable temperature profile, which is significantly cooler than typical indoor living spaces.
The corms should be packaged in a breathable container, such as a paper bag, a cardboard box, or a plastic bin modified with air holes to ensure adequate ventilation. Air circulation is necessary to prevent the buildup of stagnant, moist air around the corms, which is a primary cause of mold and rot. The corms are then nestled in a dry, insulating medium that helps buffer temperature fluctuations and regulates minimal moisture levels.
Suitable storage mediums include materials like dry peat moss, coco coir, vermiculite, perlite, or dry sand. These are used to prevent the corms from touching each other and to absorb any residual moisture. The medium should be used almost completely dry, as excessive humidity or dampness will encourage the corm to rot or break dormancy too early. The packaged corms should be placed in a dark area, as the absence of light helps reinforce the dormancy period, ensuring the stored energy is conserved for robust growth in the following spring.
Monitoring Corms During Storage
Dormancy is a state of suspended animation, but the stored corms still require periodic inspection throughout the winter months to ensure they remain healthy and viable. Checking on the corms once per month is typically sufficient to catch any potential problems before they become widespread. The primary signs of storage failure are decay, shriveling, or premature sprouting.
A corm exhibiting soft, mushy, or discolored patches is likely rotting, often due to excess moisture, and should be removed immediately from the storage container to prevent the spread of issues to healthy corms. Conversely, a corm that appears excessively shriveled or lightweight may be dehydrating, and this can sometimes be remedied by very lightly misting the surrounding storage medium to introduce minimal humidity. If a corm begins to sprout new growth while in storage, the storage temperature is likely too warm, signaling the plant to break dormancy prematurely.
Waking and Replanting Corms
The final phase of the process is transitioning the corms out of storage and into active growth, which is generally timed for late winter or early spring, about six to eight weeks before the last expected frost. The corms should be removed from their storage medium and given a final inspection, discarding any that feel soft or show signs of decay. This is also an opportunity to gently peel off any remaining papery outer skin, which can sometimes help speed up the sprouting process.
To encourage the corms to break dormancy, they need to be introduced to warmth, high humidity, and bright, indirect light. Place them in a slightly moist, soilless propagation medium like perlite, sphagnum moss, or coco coir, with the growth point facing upward. Optimal temperatures for sprouting are significantly warmer than storage temperatures, ideally in the 75–85°F (24–29°C) range, often achieved using a seedling heat mat. Maintaining high humidity, perhaps by covering the container with a plastic dome or bag, helps to trigger growth, and with patience, the first roots and shoots will emerge, signaling the successful end of the winter rest.