Is your garden (or greenhouse) going tropical this summer, with bold leaves and eye-catching hues? Then you’ll doubtless want to accent it with a plant (or three) of Colocasia esculenta. Commonly known as elephant ear, this frost-tender, warm-season perennial produces broad, prominently lobed, heart-shaped leaves that can indeed reach pachydermic proportions, giving it obvious cache for tropical-flavored planting schemes. It also comes in a wide range of colors and sizes, suggesting other design possibilities.
Its suitability for eating is what first brought Colocasia esculenta into cultivation some 10,000 years ago. Today, it remains a dietary mainstay throughout much of the tropics, represented by hundreds of varieties and nearly as many common names (including taro, dasheen, eddo, and cocoyam). As a comestible, it is prized more for its plump, starchy, underground tubers than for the long-stalked leaves that arise from them (although the leaf blades and petioles are sometimes consumed).
Most ornamental elephant ears, on the other hand, possess little food value, having been selected for looks rather than flavor. Additionally, almost all varieties (culinary and otherwise) require cooking to neutralize the acrid, needlelike molecules that lace their tissues. Uncooked tubers or leaves can cause intense discomfort if ingested. So look; don’t munch!
If what you’re looking for is something in an extra-large, an elephantine Colocasia may be just the ticket (are 3-foot leaves on 3-to 6-foot stems big enough for your tropical paradise?). Gargantuan cultivars include ‘Fontanesii’, whose dark green leaves have deep purple stems, veins, and margins; ‘Coffee Cups’, with theatrically folded, olive-green, purple-veined leaf blades atop black-purple stems; and ‘Burgundy Stem’, named for its stem color but equally remarkable for its pale green, chalky-veined, purple-suffused leaf blades. (Then, of course, there is the monstrous green-leaved Thai giant (Colocasia gigantea)). Of somewhat smaller size but equally dramatic coloration are numerous other selections such as ‘Illustris’ (black-stained, pale-veined leaves); ‘Black Magic’ (with black staining enveloping the entire leaf); ‘Mojito’ (apple-green, purplish-stemmed blades with black-purple mottling and flecking); and Electric Blue Gecko™ (slender, textured, pure black leaves with a metallic overlay).
The dwarf of the tribe, Colocasia affinis, is also well worth growing for its purple-flushed, 6-inch-long leaf blades. It’s usually represented in cultivation by ‘Jenningsii’, a deep charcoal-colored form with pale green veins and ash-gray midribs.
You might also want to take a look at the many species of Alocasia, a genus once included in Colocasia. Members of this elephant-ear clan typically bear large, corrugated, arrowhead-shaped leaves of metallic hue. The foot-long, deep green, heavily puckered leaf blades of Alocasia cuprea have a pewter overlay and sunken, burgundy-purple veins. Alocasia x amazonica brandishes gleaming, wrinkled, almost black-green leaves with silver-white veins and heavily scalloped margins. A few alocasias rival or even surpass the largest colocasias in size, with some selections and hybrids of giant taro (Alocasia macrorrhizos) producing immense leaves (as well as a trunk-like stem) from massive tubers. Giant taro’s close relatives A. odora and A. portei are of similarly jaw-dropping stature.
Growing Elephant Ears
To grow elephant ears worthy of the name, plant them a few inches deep in ample sun and fertile, humus-rich soil after the ground has warmed (tomato-planting time is ideal). Amend the planting hole with an organic medium such as Fafard Premium Natural & Organic Compost Blend, liberally so where soils are sandy or heavy. These evergreen to semi-evergreen perennials die back in fall in areas that experience frost, returning in spring if their tubers don’t freeze. Many cultivars will survive USDA Zone 7 winters under a deep leafy mulch. If necessary, plants can spend the winter indoors, either in pots (in a warm sunny niche) or as dormant tubers (stored in dry potting mix in a cool dark well-ventilated room). Or grow them year-round in a sunny warm greenhouse. A moist, fibrous, well-drained growing medium such as Fafard Ultra Container Mix works beautifully.
Colocasias and their kin achieve their greatest grandeur in regions with humid, frost-free climes (think southern Florida). A few varieties will even spread by runners, forming veritable herds of elephant ears. From the steamy Deep South to the wintry Far North, no plants are better at bringing a taste of the tropics to the garden and greenhouse.