growing under walnut trees

Asked January 22, 2017, 5:35 PM EST

perennials I can grow under a walnut tree

Jefferson County Kentucky perennials

1 Response

Juglone tolerant perennials include: astilbe; chrysanthemum (some); crocus;
ferns; wild ginger; grape-hyacinth; ornamental grasses (most); hosta (many); hyacinth; Siberian iris; peony (some); phlox; snowdrop; Solomon’s-seal; spiderwort; stonecrop; trillium; tulip; violet; winter aconite.

The difficulty is finding juglone tolerant perennials that will also tolerate competition with the Black Walnut for sun, water, nutrients and root space.

Black Walnut trees (Juglans nigra) have a naturally occurring substance called juglone that can cause yellowing, distorted growth and even death in a variety of other plants. Tomatoes and plants in the Solanacea family are especially vulnerable. Gardens, flower beds and other trees should be planted well away from black walnut trees. Leaves, stems, roots, bark and seeds (nuts) and hulls all have juglone within their tissue. I would not use black walnut leaves, sawdust or chips on a flower or vegetable garden if I could avoid it. Even composting black walnut leaves, sawdust and chips will not completely break down the juglone and sensitive plants might be affected.

Purdue has an excellent link about black walnuts, juglone and know sensitive plants that you may want to take note of:

https://www.extension.purdue.edu/extmedia/HO/HO-193.pdf

Feel free to contact our office if you have other questions.

Let me know if I can help you further!


Carol Wilder
Horticulture Technician
Jefferson County Cooperative Extension Service
502-569-2344
200 Juneau Drive
Louisville KY 40243