Black Walnut Tolerant Perennials

If you have a Black Walnut tree in your yard, you may have observed the difficulty in finding plants to thrive under their branches and in their root zone.

The root, bark and seeds of the Black Walnut (Juglans nigra) gives off a chemical, called juglone, which is toxic to many plants. In addition, the soil under a Black Walnut tends to be quite alkaline, compared to the soil outside of the tree’s root spread. (The soils in Southeastern Wisconsin tend to be naturally alkaline)

The following list was compiled from many sources. Although these perennials have exhibited a high tolerance to juglone, their appearance on this list does not imply 100% success.

If you would like to try perennials not on this list, experiment by planting a small number first. Observe the plants for at least a full growing season before adding additional plants. Yellowing or browning of leaves, stunted growth or a failure to grow, are all signs of Juglone damage.