Caladiums are popular for their vibrant, colorful foliage and are often grown as warm-season accents in gardens. The longevity of a caladium depends on two factors: the lifespan of the plant when managed correctly, and the viability of its dormant storage tuber. Understanding the plant’s natural cycle is the first step in ensuring its longevity, whether the tuber is stored for a few months or for many years.
Understanding the Caladium’s Annual Cycle
The caladium is a tropical perennial, native to the warm, humid climate of the Amazon basin. In its native environment, the plant may grow continuously or enter a brief, natural dormancy during a dry season. This perennial nature means the plant itself is designed to live for multiple years, with the tuber acting as a long-term survival mechanism.
In temperate climates, caladiums are extremely sensitive to cold and must be lifted from the ground to survive winter. Foliage begins to die back and yellow when soil temperatures consistently drop below 60°F, signaling a mandatory rest period. This is the plant’s defense mechanism: energy transfers from the leaves back into the tuber for storage. The tuber remains alive, but the gardener must dig it up and store it to prevent freezing and rot.
How Long Can Dormant Bulbs Be Stored?
When properly cured and stored, a dormant caladium tuber is generally viable for seasonal storage, spanning about six to nine months. This period typically runs from the end of the growing season in the fall until the soil warms up again the following spring. The goal of this storage is to bridge the gap between growing seasons, ensuring the tuber remains healthy enough to sprout when replanted.
A well-cared-for tuber can technically remain dormant and viable for up to a year, or even slightly longer under perfect conditions, but its vigor begins to decline the longer it remains inactive. After about 12 to 18 months of continuous storage without replanting, the internal food reserves deplete, leading to weak or erratic sprouting. Gardeners should inspect stored tubers regularly, looking for signs of a dead or non-viable specimen.
Signs of a non-viable tuber include one that feels soft or mushy, is covered in mold, or has completely desiccated and feels brittle and hollow.
Extending the Bulb’s Multi-Year Lifespan
With meticulous care during lifting and storage, a caladium tuber can survive and return for many seasons, potentially lasting 5 to 10 years or more. The tuber tends to grow larger each year it is successfully overwintered, often producing more vigorous foliage. Preparation for storage begins immediately after the foliage dies back in the fall.
The first step is curing, where newly dug tubers are allowed to dry in a warm, well-ventilated space for one to two weeks. This drying period is essential for healing any minor wounds and reducing the moisture content, which prevents rot during storage.
Once cured, the tubers must be inspected. Any soft spots or signs of rot should be cleanly cut away before dusting the surfaces with a fungicide or sulfur powder for added protection.
The storage environment is the most important factor for multi-year survival, as caladium tubers require consistently warm conditions even in dormancy. The ideal storage temperature must not drop below 50°F to 60°F. Commercial growers often suggest a warmer range of 65°F to 75°F for optimal health. Storing tubers below 50°F risks cold damage, resulting in stunted or erratic growth the following season.
Caladium tubers should be packed in a breathable medium to manage moisture loss and excessive humidity. These materials buffer the tubers from fluctuations in air moisture, helping prevent desiccation while wicking away residual moisture that could encourage fungal or bacterial growth.
Suitable breathable mediums include:
- Dry peat moss
- Vermiculite
- Sawdust
- Rice hulls
The chosen storage container, such as a cardboard box or mesh bag, should be kept in a dark, well-ventilated area. Avoid airtight plastic bags, as trapped moisture and gases can quickly lead to rot.