Thanks for mentioning that DEDON.
Where I planted mine, was in between the grapes, that had a one foot deep metal edging all around the 12 foot long, 3 to 4 foot wide bed. I used doubled over aluminum sheets that had been used for printing the local Newspaper - this was in the 1980's to the early 1990's, when these were still available. (I was told that the ink used was a soy, vegetable based ink that was not harmful to plants.) This barrier kept the weeds out and the Lysimachia clethroides roots in. Occasionally, I took excess roots out, for the Garden Club plant sales.
The Lysimachia is contained in the area at the back of the Arbour, close to the barn. There were two Interlaken grapes and one Riesling grape in this bed on the left side of the framework. They provided a canopy over the top of the Arbour which provided shade for the Lysimachia, where they thrived.
Another view of the Lysimachia clethroides bed at the end of the grapes.