Test for Juglone, released by Walnut trees?
Hi, We just bought a house and the previous owner stated that they "thought" that a tree they cut down 5-7 years ago was a walnut of some kind. Is there any kind of soil test we can do to know for sure if it was in fact a juglone-producing tree that (potentially still has) juglone lingering in the ground? If there is, since there is still a stump and roots rotting in the ground, I don't want to plant shrubs that will be killed, but I'd like to know for sure since the homeowner was so uncertain at tree identification. He said he is definitely not "a nature person," so I'm not sure about his knowledge. The stump is cut off at the ground so there isn't really any bark that I can see to try and ID the tree itself, which is why I was wondering if there was any kind of soil test available. If there isn't any juglone present in the soil, I'd hate to miss out on enjoying some of my favorite plants (like lilacs and peonies)! If there isn't a test, can you recommend anything to try? I'd like to plant flowers and also have a vegetable garden. I'm willing to build raised beds if that would enable me to grow some juglone-sensitive foods like tomatoes... Thanks for you time!
Hennepin County Minnesota
I cannot fine any test for juglone, however here is a link to information raised beds and a list of plants to avoid/try. If the stump is still present it can take many years for nature to completely break down the chemical.