Elephant Ears are big, showy plants grown for their exotic, tropical-looking leaves. Some are labeled Alocasia and some are Colocasia. What’s the difference? Inquiring minds want to know.
The easiest way to distinguish the two is to look at the leaf tips. Colocasia leaves point down. Alocasia leaves point up or appear horizontal. When plants are young, leaf direction can be difficult to determine. For a baby plant, take a look at where the stem connects to the leaf. Colocasia stems are located at the notch on the rounded end, sort of like the topmost portion of a heart shape. Alocasia stems appear to be an extension of the strong rib that runs the length of the leaf. Fun fact: Neither plant has stems. What appear to be stems are actually part of the leaf itself.
Colocasia leaves usually have a matte finish. Alocasia leaves are shiny. In general, Colocasia leaves are larger than Alocasia. Colocasia can grow to 10 feet tall. In some parts of the southeast, they have earned a reputation for invasiveness. Elsewhere, cooler temperatures keep plants in check.
It is important for the gardener to know that water needs are different between the two. Colocasia likes it wet. It will thrive in a boggy area, and is especially well-suited for pond-side gardens. Alocasia likes moisture, too, but it prefers a fast-draining soil without standing water. Too wet a soil will lead Alocasia corms to rot.
Colocasia likes sun but in intense southern sun, it prefers morning sun only and afternoon shade. Alocasia is more delicate. It likes indirect bright light and will blister if located in direct sun.
Plants rarely flower. If they do, Colocasia has a yellowish green flower, while Alocasia’s is white or cream. Flowers are not showy: a spadix surrounded by a papery spathe, visually similar to Caladium.
Alocasia is only cold-hardy in zones 10 are warmer. They are typically grown as annuals, as houseplants, or in outdoor containers that are brought inside during cold weather. Colocasia is cold-hardy in zones 8 and warmer. In a protected area and with a deep, lightweight mulch, they may survive winter in zone 7b also.
Despite the cooking preparation instructions found on the internet, all parts of both plants are highly toxic. Improper preparation can result in death. It is better to avoid eating them. People with sensitive skin should wear gloves when handling bulbs and leaves, since they can cause dermatitis.
