Juglone Tolerant Plants

Some landscape plants such as Juglans and various Carya species are allelopathic; produce a toxic substance that will suppress the growth of some species of plants within the underlying canopy area. The specific substance produced by Juglans nigra (Black Walnut) and related species is called hydrojuglone, which oxidizes into a toxic substance called juglone. This chemical is of concern when trees are encountered in the landscape, as it will limit what may be grown under or near them. Professionals are left with only two solutions to the problem, one being removal of the problem tree and the other, planting Juglone tolerant plants such as those listed below. Mature Juglans and Carya species present dramatic forms in the landscape and every effort should be made to retain healthy trees. Further reading is provided in the Ministry of Agriculture and Food information bulletin entitled Black Walnut Toxicity includedin this manual.

JUGLONE TOLERANT PLANTS

HERBACEOUS PERENNIALS

Ajuga reptans Bugleweed

Alcea rosea Hollyhock

Arisaema triphyllum Jack-in-the-Pulpit

Asarum canadense Wild Ginger

Astilbe X Garden Astilbe

Athyrium Lady Fern

Campanula latifolia Bellflower

Chrysanthemum sp. Garden Mums

Doronicum sp. Leopard’s Bane

Dryopteris cristata Shield Fern

Epimedium sp. Barrenwort

Galium odoratum Sweet Woodruff

Geranium sp. Garden Geraniums

Helianthus tuberosus Jerusalem Artichoke

Helleborus sp. Garden Hellebore

Hemerocallis sp. Daylily

Heuchera sp. Coral Bells

Hosta fortunei ‘Glauca’ Plantain Lily

Hosta lancifolia Plantain Lily

Hosta marginata Plantain Lily

Hosta undulata ‘Variegata’ Plantain Lily

Iris siberica Siberian Iris

Matteuccia struthiopteris Ostrich Fern

Mertensia virginica Virginia Bluebells

Monarda didyma Bee Balm

Myosotis sylvatica Garden-forget-me-not

Oenothera fruticosa Common Sundrops

Onoclea sensibilis Sensitive Fern

Osmunda cinnamonea Cinnamon Fern

Phlox sp. Summer Phlox

Poa sp. Blue Grass

Podophyllum peltatum Mayapple

Polemonium reptans Jacobs Ladder

Polygonatum commutatum Solomon’s Seal

Polystichum sp. Christmas Fern

Primula sp. Garden Primrose

Pulmonaria sp. Lungwort

Sanguinaria canadensis Bloodroot

Sedum sp. Sedum

Stachys sp. Lamb’s Ears

Tradescantia virginiana Spiderwort

Trillium sp. Trillium

Uvularia sp. Uvularia

Viola sp. Violets

Vinca minor Common Periwinkle

JUGLONE TOLERANT PLANTS

BULBS

Chionodoxa luciliae Glory of the Snow

Crocus sp. Garden Crocus

Endymion hispanicus Spanish Bluebell

Eranthis hyemalis Winter Aconite

Galanthus sp. Snowdrops

Hyacinthus sp. Hyacinthus

Muscari sp. Grape Hyacinth

Narcissus sp. Daffodils

Scilla siberica Siberian Squill

Tulipa sp. Tulips

JUGLONE TOLERANT PLANTS

TREES

Acer palmatum Japanese Maple

Carya sp. Hickories

Catalpa sp. Catalpa

Juniperus virginiana Red Cedar

Picea abies Norway Spruce

Quercus sp. Oaks

Syringa sp. Lilac

Tsuga canadensis Canada Hemlock

JUGLONE TOLERANT PLANTS

VINES AND SHRUBS

Clematis sp. Clematis

Daphne mezereum Daphne

Euonymus alatus Burning Bush

Forsythia sp. Forsythia

Hibiscus syriacus Rose of Sharon

Kolkwitzia amabilis Beauty Bush

Lonicera tatarica Tattarian Honeysuckle

Parthenocissus quinquefolia Virginia Creeper

Philadelphus sp. Mockorange

Rhododendron

‘Pinxterbloom’ Pinxterbloom Azalea

‘Gibraltar’ Gibraltar Azalea

‘Balzac’ Balzac Azalea

Rubus occidentalis Black Raspberry

Viburnum lantana Wayfaring Tree

JUGLONE TOLERANT PLANTS

ANNUALS

Begonia sp. Begonia

Calendula sp. Calendula

Ipomea sp. Morning Glory

Viola sp. Pansy

Note: Where a Genus is listed most species are also tolerant of Juglone, additionally; where a species is listed most cultivars of that specific species will be tolerant of Juglone.