Planting after Walnut tree
We had an aging walnut tree removed last fall. The stump was ground up but the chips are still there. Can I plant another tree in the same spot?
Lane County Oregon
Thanks for your question. There are actually some plants that can be planted near walnut trees, because they are tolerant of the juglone chemical that the tree produces. As this source indicates, "The highest concentration of juglone occurs in the soil directly under the tree’s canopy, but highly sensitive plants may exhibit toxicity symptoms beyond the canopy drip line. Because decaying roots can release juglone, toxicity may occur for several years after a tree has been removed."
So, you are wise to ask! But, if you will read further in the article to which I directed you, there are dozens of plants that are tolerant of juglone, even when the tree is there. Many of the plants listed are actually native to the Pacific Northwest, and you can cross-check them using this Native Plant Guide for the Willamette Valley.
Hope these are helpful. Good luck!