Elephant ears (Colocasia and Alocasia genera) are popular ornamental plants known for their dramatic, heart-shaped foliage. However, their vigorous growth, particularly that of Colocasia esculenta (Taro), can make them invasive and difficult to manage. The main challenge in eradication is the plant’s persistent, energy-storing underground structures—corms or tubers. These corms act as an energy reservoir, allowing the plant to regrow even after the foliage is removed, requiring a methodical approach for permanent control.
Physical Removal Techniques
The most thorough, non-chemical method for elimination is manual excavation, which requires removing the entire subterranean structure. Start by cutting the large leaves and petioles (stems) close to the ground to improve visibility and access. Be cautious, as the sap contains calcium oxalate crystals which can irritate the skin; wearing gloves and long sleeves is necessary.
Once the foliage is cleared, dig widely around the plant’s base. Corms can be buried deeply, sometimes requiring excavation down to two or three feet to ensure complete removal. The goal is to extract the main corm along with every attached offset or tuber, as even a tiny fragment left behind can sprout into a new plant. Digging when the soil is moist and soft makes lifting the heavy corms easier.
Smothering or solarization provides an alternative for managing extensive patches without digging. This method involves covering the area with an opaque material, such as thick black plastic sheeting or heavy cardboard, weighted down or covered with mulch. The lack of light prevents photosynthesis, starving the corms of energy. This process is slow and may need to be maintained for six months to a full year to be fully effective.
Chemical Strategies for Eradication
For dense infestations or when physical removal is impractical, systemic herbicides offer effective control. Products containing concentrated glyphosate are recommended because the herbicide is absorbed by the foliage and travels down into the corm. However, the waxy coating on elephant ear leaves can repel spray, necessitating the use of a surfactant additive to help the chemical adhere and penetrate.
Targeted Cut-and-Paint Method
A more targeted and effective approach is the “cut-and-paint” method, which bypasses the waxy leaf barrier entirely. This technique involves cutting the leaf petiole a few inches above the ground and immediately applying a concentrated, undiluted glyphosate solution directly to the fresh cut surface. Applying the herbicide within seconds of cutting is important, as the plant quickly forms a seal that prevents chemical absorption.
The cut-and-paint method minimizes environmental impact by limiting application strictly to the plant’s vascular tissue, reducing the risk of runoff or damage to surrounding plants. When using any herbicide, safety precautions are mandatory and must be followed precisely according to the product label instructions, including wearing PPE such as gloves and protective eyewear.
Ensuring Permanent Control
The most frequent cause of failure in elephant ear eradication is improper disposal of removed plant material, which can lead to re-infestation. Corms and their offsets must never be added to a compost pile, as they possess enough stored energy to sprout and grow. Instead, all excavated corms, tubers, and foliage should be bagged tightly in heavy-duty plastic trash bags and discarded with household waste.
After the initial removal, the treated area requires a long-term monitoring strategy because underground structures may not all be destroyed in a single effort. The area should be checked regularly for several months, or into the next growing season, for any signs of new sprouts emerging from residual corm fragments. These emergent sprouts indicate that a portion of the energy reservoir survived the initial treatment.
Any new growth must be addressed immediately to prevent the plant from establishing new energy reserves. Small sprouts can be removed by immediate re-digging to extract the tiny cormlet. Alternatively, these new leaves can be spot-treated with a systemic herbicide, ensuring the chemical reaches the small, newly active root structure before the plant matures. Persistence in this follow-up phase is the most important factor for achieving permanent eradication.