Answer: Hedera helix or English ivy is used as a groundcover because it does spread and is very sturdy plant. It is often planted in areas where a healthy lawn will not grow, such as in shade or in poor soil, because it is extremely vigorous and grows well in a wide variety of conditions. For the same reasons it makes a good groundcover, it can be difficult to deal with where it is unwanted.
There are several approaches to this. First, you need to prevent the new growth from spreading outward beyond the boundary you wish to establish. This can be achieved by regular trimming and by ripping out the longer stems, pulling them by the roots. There are some growth regulating chemicals that can be used, although not always available to homeowners. You might check with your local Cornell Cooperative extension to see what is available in New York state for professional or homeowner application.
Next, you can try to eradicate it altogether. To do this usually requires use of a non selective herbicide such as products containing glyphosate. If you opt to try this route, be sure to read and follow all of the label instructions, including waiting periods between application and removal of the surface growth. This is important so that the chemical has sufficient time to be translocated into the roots where the plant is ultimately killed. Herbicides may require several applications to be effective.
You can also try to dig it out by the roots or smother it with a layer of heavy cardboard topped with mulch. These are labor intensive methods and can take repeated attempts over several years to achieve results.
I should point out that in some cases it is easier to work with the ivy and use it as a groundcover rather than to replace it with lawn. It does have a similar visual effect in the landscape in that it provides a plain green backdrop. It is also far less maintenance than a lawn would require.
Good luck with your project!
Q&A Library Searching Tips