Plants Known to Grow Under Black Walnut Trees

Courtesy of Ohio State University Extension Factsheet HYG-1148-93
http://ohioline.ag.ohio-state.edu/hyg-fact/1000/1148.html

The roots of Black Walnut (Juglans nigra) produce a substance known as Juglone (5-hydroxy-alphanapthaquinone). Many plants may be injured or killed within one to two months of growth within the root zone of these trees. The toxic zone from a mature tree occurs on average in 50 to 60 foot radius from the trunk, but can be up to 80 feet. The area affected extends outward each year as the tree enlarges.

Not all plants are sensitive to Juglone. Many trees, vines, shrubs, groundcovers, and perennials will grow in close proximity to walnut trees. A short list of native perennials that have been observed growing near black walnut trees is listed below:

Wildflowers

Wood Anemone - Anemone quinquefolia

Virginia Spiderwort - Tradescantia virginiana

Spring Beauty - Claytonia virginica

Nodding Trillium - Trillium cernuum

Dutchman’s Breeches - Dicentra cucullaria

Large Flowered Trillium - Trillium grandiflorum

**Jerusalem Artichoke - Helianthus tuberosus **

Merrybells - Uvularia grandiflora

Virginia Waterleaf - Hydrophyllum virginianum

Canada Violet - Viola canadensis

Beebalm - Monarda didyma

Woolly Blue Violet - Viola sororia

Bergamot - Monarda fistulosa

Mayapple - Podophyllum peltatum

Ferns

Jacob's Ladder - Polemonium reptans

Crested Woodfern - Dryopteris cristata

Great Solomon's-Seal - Polygonatum canaliculatum

Sensitive Fern - Onoclea sensibilis

Bloodroot - Sanguinaria canadensis

Cinnamon Fern - Osmunda cinnamomea

** BEWARE, this plant is invasive