Caladiums, often called “fancy-leaf caladiums,” are tropical foliage plants prized for their vibrant, heart-shaped leaves that thrive in shaded garden spaces. These striking plants are grown from underground storage organs that, while commonly referred to as bulbs, are technically tubers. Planting these tubers correctly is the most important step in ensuring a successful season of lush, colorful growth. Proper orientation in the soil directly determines how efficiently the plant can sprout and establish its root system.
Identifying the Caladium Bulb Structure
The structure of a caladium tuber is irregular and asymmetrical, often leading to confusion during planting. Unlike the neat, concentric layers of a true bulb, the caladium tuber is a thickened stem that stores nutrients. This anatomy dictates the correct planting position, as the tuber has a distinct top and bottom.
The top side of the tuber is typically rougher, more knobby, or slightly pointed, concentrating the growth points, known as “eyes.” These eyes are dormant buds where the leaf shoots will emerge. Conversely, the bottom side is generally smoother, flatter, or sometimes slightly concave, and it is the area from which the roots will develop.
When inspecting the tuber, you may notice one large, central bud surrounded by several smaller, lateral eyes. This central bud is the most dominant growth point. Understanding the anatomical difference between the bumpy, eyed top and the smooth bottom is the foundation for correct placement in the soil.
Planting Orientation: Finding the “Eyes”
Successfully planting a caladium requires placing the tuber in the ground with the bumpy, “eyed” side facing directly upward. This ensures the emerging leaf shoots have the shortest path to the soil surface and sunlight. If planted upside down, the shoots must expend significant energy curving around the tuber to reach the surface, delaying and weakening the initial growth.
Focus on locating the cluster of small, dimpled bumps resembling miniature potato eyes. These growth points are the precise locations where the petioles, or leaf stalks, will begin to push out. Some commercial growers even mark the correct upward-facing side with a spot of paint to eliminate guesswork.
Once the top is identified, the flatter, root-producing side must be placed firmly down into the planting hole. Orienting the tuber with the eyes up allows the roots to grow immediately downward, anchoring the plant and beginning nutrient uptake. This correct vertical alignment maximizes the plant’s initial energy expenditure on foliage production rather than correcting its orientation underground.
Addressing Ambiguous or Damaged Bulbs
Sometimes a caladium tuber may be so irregular in shape that the eyes are not clearly defined, or the tuber may be damaged. When the top and bottom are indistinguishable, planting the tuber horizontally, or on its side, is the recommended solution. This method allows gravity and the plant’s natural phototropism to guide the shoots upward and the roots downward, though it may take slightly longer for the plant to emerge.
For larger, healthy tubers, a common practice is to intentionally remove the large central eye, a process known as “de-eyeing.” This technique is performed by carefully scooping out the dominant central bud with a clean, sharp knife. Removing this main bud eliminates apical dominance, which is the suppression of lateral bud growth by the primary bud.
By removing the central eye, the tuber activates the surrounding smaller, lateral eyes, resulting in a bushier plant with a greater number of leaves. This provides a fuller, denser display of foliage, though individual leaves may be slightly smaller than those produced by a tuber with an intact central bud. After de-eyeing, the tuber should be allowed to heal for a day or two before planting.
Essential Planting Depth and Soil Preparation
After correctly orienting the tuber, ensure it is placed at the proper depth within suitable soil conditions. Caladium tubers should be planted shallowly, 1.5 to 2 inches below the soil surface, measured from the top of the tuber. Planting too deeply can delay or prevent the shoots from emerging, while planting too shallowly can cause the tuber to dry out.
The soil needs to be light, well-draining, and rich in organic matter to promote healthy root development and prevent rot. Amending the planting area with compost or well-rotted manure achieves the necessary balance of drainage and fertility. Caladiums thrive in a loose substrate that allows for easy expansion and unimpeded root growth.
In garden beds, space the tubers 8 to 12 inches apart, depending on the desired density and the mature size of the cultivar. Adequate spacing ensures each plant receives sufficient light and air circulation, helping to prevent fungal issues. Consistent moisture is necessary for germination, but well-draining soil prevents the tubers from sitting in soggy conditions, which can lead to rapid decay.