English ivy, yay!
I have a patch of English ivy in my yard that I'm working on removing. We've removed all the top groundcover, leaves, stems and smaller roots, but there is quite a large root system (I think it's an old patch). Some roots are quite deep and large. What tips and tricks do you have for killing off the root system? The patch is under a large silver maple and small Japanese maple that I want to keep. Eventually, I'd love to plant some native plants to attract butterflies and birds. I'm hesitant to plant anything this year until we can get more of the roots removed. Should I continue to hack away at the roots, cover them with cardboard and mulch, try targeted application of glyphosate? I'm not a chemical friend and am worried about it damaging the trees, but if it works...
Controlling English ivy is quite a challenge. As you know they form extensive root systems. They can spread and reproduce both from stems that root as they touch the earth, and from the berries which the birds eat and carry long distances from the mother plant.
Control measures require determination and persistence. There are two main methods of control: 1. manual - pulling, mowing, and digging of the plant or mulching with cardboard and 2. chemical control. You've already done alot of manual control, which is great. With a perennial weed like ivy one treatment is never enough. You can dig all the roots out the area, but will probably miss a few. The goal has to be to deplete the nutrients stored in the roots, otherwise the plant will come back. Every time the roots have to send up a new shoot, they use of some of their stored nutrients. The leaves produce those nutrients, so you want to destroy any leaves that emerge. You can deplete the roots by continuing to pull the plants, depriving them of sunlight with the cardboard mulch, or by spraying any new plants with either glysophate (Round-up is one brand) or trichlopyr (brush killer is usually trichlopyr). Ivy develops a waxy coating that protects it from herbicides; so treating the new leaves which won't have had time to develop the coating makes the herbicides more effective. Whatever you choose, if you keep at it you can be successful. It can take a couple of years to completely eradicate ivy.
This article, English Ivy Control, gives additional information.