Elephant ears (Colocasia or Alocasia) are popular tropical plants cultivated for their expansive, dramatic foliage. They are grown from a corm or tuber, and successful growth hinges on planting it with the correct orientation. Incorrectly positioning the corm can delay germination or prevent the plant from establishing itself. Identifying the top and bottom of the corm is the first step toward enjoying these lush specimens in your garden.
How to Identify the Top and Bottom of the Bulb
Proper planting requires locating the growing point, which must face upward toward the soil surface. This growth zone often appears as a slightly pointed tip, sometimes called the “eye” or bud, where the previous stem was attached. The top of the corm may also display light-colored, concentric rings indicating where new foliage will emerge.
The rooting end, which must face down, is typically the flatter, rougher side of the corm. This is where the fibrous roots will develop. If the corm is roughly spherical or the orientation is unclear, plant it horizontally on its side. The plant will still send its foliage shoots upward and its roots downward.
Preparing the Soil and Timing the Planting
Elephant ears require warm soil conditions to break dormancy. Wait until all danger of spring frost has passed and the soil temperature consistently registers at least 65°F. Planting too early in cold soil will cause the corm to rot before it can sprout.
The ideal planting medium is rich, moist, and well-draining. Incorporating organic matter, such as compost or aged manure, improves fertility and moisture retention. While Alocasia varieties prefer well-drained conditions, Colocasia varieties thrive in consistently wet areas. Both benefit from a site that receives full sun to partial shade, avoiding intense midday heat.
Step-by-Step Guide to Planting Depth
The planting depth for the corm is determined by its size, ensuring it is adequately insulated and supported in the ground. Dig a hole deep enough so the corm’s top is covered by one to two inches of soil. For larger corms, this means setting the bulb approximately four to six inches deep in the planting bed.
Place the corm in the hole with the growing point facing up, or on its side if the orientation is ambiguous. Gently backfill the hole with the enriched soil, ensuring no large air pockets remain. Consider the mature size of your specific variety, as some can reach several feet wide, and space the corms two to six feet apart to prevent overcrowding.
Early Care for Emerging Elephant Ears
After planting the corm, water the area thoroughly to settle the soil and initiate growth. Maintaining consistent soil moisture is important, as these plants are heavy water consumers once established. Expect a waiting period of two to four weeks before visible growth appears above the soil surface.
Once the first shoots have emerged, begin a regular fertilization schedule. Elephant ears are heavy feeders and respond well to a balanced liquid fertilizer applied every two to three weeks. This consistent nutrient supply supports the rapid growth of the large leaves throughout the growing season.