Planting Under Black Walnut Trees

We’re often asked about planting under Black Walnut trees. Black Walnut trees can be difficult to garden around as the tree roots exude the toxin Juglone, which permeates the soil and prevents many plants from growing under the tree and even beyond 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 many native plants that will grow under and around Black Walnuts. Here are some of our favorites:

Amsonia tabernaemontana
Aquilegia canadense (Columbine)
Arisaema triphyllum (Jack-in-the-Pulpit)
Asarum canadense (Wild Ginger)
Aster sp. (Aster)
Carex sp. (Sedges)
Caulophyllum thalictroides (Blue Cohosh)
Dicentra cucullaria (Dutchman’s Breeches)
Geranium maculatum (Wild Geranium)
Iris versicolor (Blue Flag Iris)
Lobelia siphilitica (Great Lobelia)
Mertensia virginica (Virginia Bluebells)
Monarda fistulosa (Wild Bergamot)
Podophyllum peltatum (Mayapple)
Phlox divaricata (Wild Blue Phlox)
Polimonium reptans (Jacob’s Ladder)
Sanguinaria canadenses (Bloodroot)
Sedum ternatum (Stonecrop)
Solidago spp. (Goldenrods)
Thalictrum dioicum (Early Meadowrue)
Trillium spp.
Uvularia grandiflora (Bellwort)
Viola spp. (Violet)

FERNS
Osmunda cinnamomea (Cinnamon Fern)
Polystichum acrostichoides (Christmas Fern)

SHRUBS
Cornus racemosa (Grey Dogwood)
Corylus americana (American Hazelnut)
Euonymus atropurpureus (Eastern Wahoo)
Hamamelis virginiana (Common WitchHazel)
Viburnum spp. (Viburnums)

Big Leaf Aster (Aster macrophyllus)

Big Leaf Aster (Aster macrophyllus)

Prairie Nursery’s No Mow Lawn also grows well under walnut trees:

No Mow Lawn

No Mow grass area under the walnut trees in the Prairie Nursery display garden.