Years ago I was renting in a rural setting, and decided I would like to plant a garden.
The only space available was a knoll that was adjacent to a corn field and loaded with sumac. We removed the sumac by digging up the roots as much as possible and pulling the plants our with the roots attached as much as possible. We then applied a generous amount of calcium carbonate (lime) to the area, turned the soil a final time, and planted one of the most glorious gardens I have ever tended.
Sumac likes acidic soil, so it did not return.
