We’re often asked about planting under Black Walnut trees. Black Walnut trees are difficult to live with as the tree roots exude the toxin Juglone, which permeates the soil and prevents many plants from growing under the tree as distant as 50-80 feet (depending on who you talk to) from the drip line.
Question: Is the New Jersey Tea plant Black Walnut tolerant?
Answer: According to several sources, New Jersey Tea (Ceanothus americanus) is not resistant to Black Walnut. You can confirm this on Michigan State University’s Extension website. There are a native plants that will grow under and around Black Walnuts (but not as many as we would like!). Here are a few of our favorites:
Arisaema triphyllum (Jack-in-the-Pulpit)
Asarum virginicum (Wild Ginger)
Aster spp. (Aster)
Carex spp. (Sedges)
Caulophyllum thalictroides (Blue Cohosh)
Dicentra cucullaria (Dutchman’s Breeches)
Geranium spp. (Wild Geranium)
Iris spp.
Lobelia siphilitica (Great Lobelia)
Monarda fistulosa (Wild Bergamot)
Podophyllum peltatum (Mayapple)
Polimoniaceae spp. (Phlox)
Sedum ternatum (Stonecrop)
Solidago spp. (Goldenrod)
Trillium spp.
Uvularia perfoliata (Bellwort)
Viola spp. (Violet)
Osmunda cinnamomea (Cinnamon Fern)
Polystichum acrostichoides (Christmas Fern)
Prairie Nursery’s No Mow Lawn also grows well under walnut trees:
No Mow grass area under the walnut trees in the Prairie Nursery display garden.
Can you use holly shrubs under walnuts?
Hi Carlynn, Yes, I have seen American Holly (Ilex opaca) listed as a Juglone tolerant shrub. Click here for a link to the source.
Great list!
I have a large black walnut in my yard where I’ve done a woodland restoration (it was formerly lawn).
Native shrubs doing really well: Nannyberry Viburnum, American Hazelnut
Native perennials: Wild Columbine, Wild Geranium, Woodland Phlox, Penn Sedge, Wild Ginger, Early Meadowrue, Downy Yellow Violets, Zigzag Goldenrod
Thanks for the additions… We’ll keep growing the list!
My Dutchman’s Breeches and Blue Cohosh do just fine under my black walnut trees.
Ed, thanks for the tip. We added those species to our inventory just this year, maybe that’s why they weren’t on there. I’ll put them on the list. -mary