Hello David,

Aegopodium podagraria, commonly called ground elder, bishop’s weed, snow on the mountain… is a highly aggressive ground cover that spreads by underground stolons and can easily overrun and choke out desirable plants.

While not officially on the Michigan Invasive Species list, states around us classify ground elder as an invasive species.

Having said that, there are only two methods of control: physical removal and use of a non-selective herbicide. Digging out the plants allows you to follow the underground stems (stolons) by which the plant spreads, in order to remove daughter plants that have not even broken ground yet. Using an herbicide such as glyphosate must be thorough in order to kill the extensive root and stolon system below ground. It may take several applications of glyphosate to completely eradicate the plants. Glyphosate applications are also more effective in the fall when the plant is naturally moving sugars to the roots for winter storage. This moves the herbicide to the roots as well, causing a more noticeable effect.

There is one method I have heard of that works very well. In the spring, cover the entire infected area with tarps just as the leaves are breaking ground. Leave the tarps in place for at least a full year. In order to do this, you would need to dig out the hostas and lily of the valley that you want to save and plant them in a holding bed. Then one or two seasons later, when all the ground elder is killed off, re-establish your bed area. When you dig out the desirable plants you need to carefully look for stolons of the ground elder to make sure you are not transferring the problem to the holding bed. Another word of advice – do not plan on keeping a stand of ground elder – it will always break containment and invade your desirables. You will want to eradicate it completely.

Here are some good references to consider:

https://www.canr.msu.edu/resources/goutweed-aegopodium-podagraria

https://dnr.wisconsin.gov/topic/Invasives/fact/BishopsGoutweed

Good luck with your project!