Caladiums, known for their vibrant, heart-shaped foliage, grow from underground tubers, often called bulbs, which enter dormancy. When their lush leaves fade, leaving behind what appears to be a lifeless bulb, it can be concerning. This guide provides methods to determine if your caladium bulbs are still viable for the next growing season.
Understanding Caladium Dormancy
Caladiums are tropical perennials that naturally undergo a dormant period, especially in cooler climates or during shorter daylight hours. This dormancy is a survival mechanism, allowing the plant to conserve energy when growing conditions are not ideal. During this phase, foliage typically yellows, wilts, and dies back, leading many to believe their bulbs are dead.
A dormant caladium bulb rests, preparing for new growth when favorable conditions return, usually in spring. While the visible plant may disappear, its life force remains stored within the tuber. This resting phase is a normal and beneficial part of the caladium’s life cycle, contributing to stronger, more vibrant foliage in subsequent seasons.
Visual and Tactile Checks for Bulb Health
Before more invasive methods, perform visual and tactile inspections to assess your caladium bulb’s health. A healthy, viable bulb should feel firm and plump, indicating it retains moisture and energy. Its surface should appear uniform in color, brown or reddish-brown, without significant discoloration. Small nubs or “eyes” may also be observed, which are points where new growth will emerge.
Dead or unhealthy bulbs show specific signs. Mushy, soft, or squishy bulbs indicate rot, often from excessive moisture during storage. Shriveled or brittle bulbs suggest severe dehydration, making them unlikely to recover. Mold, dark spots, or a foul odor also indicate rot or disease; discard them to prevent pathogen spread.
The Viability Test
When visual and tactile checks are inconclusive, a “scratch test” can provide a definitive answer regarding your caladium bulb’s viability. This involves carefully removing a small portion of the outer layer to examine the tissue underneath. Select an inconspicuous spot, such as near the base.
Using a clean, sharp knife or fingernail, gently scratch away a tiny section of the outermost skin. A viable bulb reveals firm, moist, light-colored flesh underneath (white, cream, or light green). This indicates living tissues capable of sprouting. If the exposed area is dry, dark, brown, or black, or if the bulb feels hollow or rotted, it is likely dead.
Next Steps for Your Caladium Bulbs
After assessing your caladium bulbs, next steps depend on their viability. If firm, healthy, and showing life through the scratch test, they are ready for replanting. To encourage sprouting, warm them to above 60°F (16°C) and provide a slightly moist, well-draining potting mix. Planting them when soil temperatures reach around 65°F (18°C) ensures successful emergence.
Conversely, if confirmed dead (mushy, shriveled, moldy, or dark/dry interiors), discard them. Planting dead bulbs yields no results and can introduce diseases. Common reasons for death include improper storage, such as temperatures below 60°F (16°C) or freezing, which cause internal damage. Excessive moisture during dormancy also leads to rot, while overly dry conditions cause desiccation. Store bulbs in a cool, dry, well-ventilated area, often in peat moss or sawdust, to prevent these issues.