Taxonomy and Botany of Elephant Ears
Plant taxonomy classifies the most widely known elephant ear plants, or "taro," as Colocasia esculenta. But plants of the Alocasia genus and of the Xanthosoma genus can go by the same common name, as well. A number of cultivars also exist, including types with dark leaves (for example, C. esculenta 'Black Magic'), placing them among the so-called "black plants."
Planting Zones, Sun and Soil Requirements
In planting zone 8 and above, elephant ears can be left outside year-round. They are not native to Florida but have become naturalized in some wetland areas in the southern half of the state and are widespread. In fact, they are considered invasive there. In cold climates, the plants are treated as annuals, allowing us our own little piece of tropical landscaping, albeit short-lived. But they can be brought indoors for winter to extend their lives (see below).
Grow elephant ears in a slightly acidic soil in partial shade. As a wetland plant in the wild, elephant ear plants like a lot of water. This makes them a good choice for wet areas where homeowners usually have trouble finding suitable plants.
Characteristics of This Tropical Plant
In landscaping, elephant ears are grown for their large, heart-shaped leaves. While these leaves can reach 3 feet long and 2 feet wide in the tropics, in the North they will remain smaller, but still impressive. The plants can grow 8 feet tall in the tropics; in the North, a height of 2-3 feet is more common (depending on growing conditions).
Uses in Landscaping, Origin of the Botanical Name
In the North, treat elephant ears as annuals. Take advantage of their large, attractive foliage and grow them among your other plants, thus varying the texture in a planting bed. Do not sell this plant short simply because it lacks showy flowers. Landscaping pros know it, and the public is starting to catch on: You can rely on pretty leaves longer than you can flowers. Elephant ears is just one example of a plant valued for the display put on by its leaves.
Their thirst for water makes elephant ears effective not only in soggy areas of the landscape, but also near water features. One option is to grow them in containers and let them complement smaller plants for water gardens. With their huge, shield-shaped leaves, they create a nice contrast with another favorite used around water gardens, the horsetail, which pushes up multiple green spear-like shoots from its base.
Elephant ears' species name, esculentia, is the same term that gives us the word "esculent," meaning edible. In fact, elephant ears are an important food source around the world, in warm climates (for more, see below).
Elephant ears are heavy feeders. Fertilize them with a fertilizer high in nitrogen.
These tropical foliage plants are tender but can be overwintered in cold climates. Just dig up the corms and keep them in a cool, but not freezing basement or garage, as you would store canna bulbs, dahlia tubers, etc. While they are in storage for the winter, make sure the corms neither rot nor totally dry out. Replant them in spring when danger of frost has passed.
A number of cultivars of elephant ears have made a name for themselves for the striking colors of their foliage. Many, in addition to the 'Black Magic' cultivar, have leaves with quite a bit of black color in them. Here are some examples:
- 'Black Coral' is all black.
- 'Illustris': black, with green edging and veining.
- 'Jet Black Wonder': a white veining pattern stands out sharply against a black background.
Cultivars with yellow or chartreuse in them are also popular:
- 'Lime Zinger' is chartreuse.
- 'Maui Gold' is golden-chartreuse.
- 'Yellow Splash' has a variegated leaf of yellow and green, making it look rather like the pothos plant so widely used as a houseplant.
Elephant Ears and Edible Landscaping: Taro Root
For those of us interested in the ornamental value of C. esculenta, the common name, "elephant ears" is apt, since we are impressed with the size of its leaves. But those interested in the edible value of the plant think of it as "taro" or "coco yam," in which case the focus is usually on its root, or corm.
According to Wilfred Lee ("Ethnobotanical Leaflets," Southern Illinois University, Carbondale, 1999), "Taro constituted the staff of life for the Hawaiians when Captain Cook arrived in the islands in 1778. At that time an estimated three hundred thousand people in the islands lived chiefly on poi (a fermented or unfermented taro paste), sweet potato, fish, seaweed, and a few green vegetables and fruits."
In spite of this fact, all parts of elephant ear plants can upset the stomach if ingested without being properly cooked first. Plus the sap can be a skin-irritant.