How to Kill Elephant Ear Plants
Do not compost elephant ear plants if you are trying to kill them. They will just start growing in the new location.
Generally, traditional plant and weed killers do not work on elephant ears because they are extremely hardy. The concentrations necessary can hurt your other plants and grass and contaminate your groundwater.
Elephant ear plants are a popular landscaping plant with broad, flat, green leaves. Most people plant them deliberately, but if they are not carefully controlled, they can take over your entire yard. Their roots run very deep, and if you do not remove the entire plant, not only will it return, but often the pieces of the roots left underground will also grow new elephant ears. The removal process is relatively straightforward, but you may need to repeat the process multiple times before you achieve full success.
Work on your elephant roots when the soil is very moist. The wetter and looser the soil, the easier it will be to remove the entire plant in one piece from the earth. Hard, dry soil makes it more likely that you will leave pieces of the plant in the ground or break off pieces of the root. If you cannot wait for rainfall, dampen the area around the elephant ears thoroughly and prepare to get a little muddy.
Clip off the broad tops of the plant. You need to remove the big, flat leaves so that you can see where you are working. Leave the stems tall and in place so that you can be sure to remove every plant. Put the leaves directly into the garbage bags as soon as you clip them.
Rake the soil away from the stems of the plants. Expose as much of the stem and root system as possible, using the rake. Do not scrape the stem or the roots while you are raking. Be gentle.
Loosen the plant from the ground gently. Hold the stem firmly and as far down as possible. Wiggle the stem back and forth to loosen the hold of the roots in the soil. If you have trouble getting the plant loose, you may want to add some more water from the hose to the area around the plant to loosen up the soil and make it harder for the roots to hold on.
Use your spade if necessary. A spade can cut off pieces of the roots, which will result in more elephant ear plants growing in place of the old ones. Only use the spade if you need to dig out around the elephant ear plant. Avoid using it close to the stem. As soon as you reveal roots, start wiggling and raking again.
Remove the entire plant, including the whole root system, from the ground intact. Place the entire plant in the trash bag right away. If you wish, you can shake off loose dirt, but be careful not to leave any pieces of the plant in your yard. Once you dispose of the entire plant, you can be sure that it will die in the trash bag away from your yard.