This plant was considered most powerful when gathered at Kupalo (The Summer Solstice). One could control demons and troublesome spirits with the root if the following words were chanted over it before a sacred image:
You have wept long and much but gained little.
May your tears not drown the open field...
... I am so sorry to do this to you, but this post has been moved to my new website, Magickal Ingredients, and can be found in its entirety here: Purple Loosestrife Magick and Lore
As you explore this site, you may find links to a "page not found" instead of something cool and magickal. For this I apologize. I am very working hard behind the scenes to restore those pages along with a link to their homes on my new website where they can be viewed in full.