PlantLife Online

Answer

Because elephant ear plants (Colocasia) spread through their roots digging them up will only work if you remove every piece of the roots. Organically you could starve them of all water but this could be time consuming and in some places may be impossible or if you have patients and dedication cut or pull each new leaf as it emerges, overtime they will not have the energy to produce new leaves. The other option is to spray the plant with a herbicide, most herbicides work by absorbing the chemical through the leaf membrane so let the plant put out a few leaves before you apply. It may take a few applications. If your elephant ear plants are near a pond or other water feature read the pesticide label closely!