The elephant ear plant (Colocasia esculenta) is a shade-loving perennial known for its colorful foliage, which comes in colors like green and purple. Though elephant ears are a favorite among shade gardeners, the plants can grow unruly and need to be controlled. Containing the plants can be as easy as pulling out seedlings as they develop. But gardeners who no longer want to keep their elephant ear plants can employ several tactics to kill and eradicate these perennials from their garden space.
Remove the elephant ear plant by hand. Manual removal is best for seedlings and juvenile elephant ear plants. Grab the plant at its base and pull upward, away from the soil. Discard the plant, or lay it in the sun to dry it out and kill it before adding the plant to your compost heap.
Mow down the elephant ear plants with a string trimmer. Repeated mowing once a week will keep the plants from sending up new shoots. Without energy-creating foliage, the plants' roots will starve over the course of several weeks and die.
Spray the elephant ear plants with a glyphosate-based herbicide. This is best for mature elephant ear plants that have already reached their maximum height of 1 to 2 feet. Put on gloves and eye goggles before you mist the entire surface of the elephant ear plant with the herbicide. It will die within 10 days.