Toxins from Black Walnut tree!

[Sis]

I have a partly wooded backyard with many Black Walnut trees. Many plants,trees and shrubs won't survive when grown close to them Does any kind person have experience in growing anything near them?One of the things I want to plant are hemlock trees nearby. Can anyone give me some advice on that and/or other trees/shrubs? Thanks. S.

[David J Bockman]

Because of a substance produced by the Black Walnut's roots (called 'Juglone'), many plants will not thrive or even live within their driplines. There *are* plants that are not affected by Juglone. From

"The following landscape plants have been observed to be tolerant to juglone: arborvitae, autumn olive, red cedar, catalpa, clematis, crabapple, daphne, elm, euonymous, forsythias, hawthorn, hemlock, hickory, honeysuckle, junipers, black locust, Japanese maple, maple (most), oak, pachysandra, pawpaw, persimmon, redbud, rose of sharon, wild rose, sycamore, viburnum (most), Virginia creeper."

Dave

[Frank Logullo]

You might check here:

[Beecrofter]

"Sis" wrote in message news:...

Taken from Ohio State University Extension web page

Observed Growing Under or Near Black Walnut* Trees

• Japanese Maples, Acer palmatum and its cultivars * Southern Catalpa, Catalpa bignonioides * Eastern Redbud, Cercis canadensis

• Canadian Hemlock, Tsuga canadensis

Vines and Shrubs

• Clematis 'Red Cardinal' * February Daphne, Daphne mezereum * Euonymus species * Weeping Forsythia, Forsythia suspensa * Rose of Sharon, Hibiscus syriacus * Tartarian Honeysuckle, Lonicera tatarica, and most other Lonicera species * Virginia Creeper, Parthenocissus quinquefolia * ** Pinxterbloom, Rhododendron periclymenoides * **'Gibraltar' and 'Balzac', Rhododendron Exbury hybrids * Multiflora Rose, Rosa multiflora * Black Raspberry, Rubus occidentalis * Arborvitaes, Thuja species

• ** Koreanspice Viburnum, Viburnum carlesii, and most other Viburnum species

Annuals

• Pot-marigold, Calendula officinalis 'Nonstop' * Begonia, fibrous cultivars * Morning Glory, Ipomoea 'Heavenly Blue' * Pansy Viola

• Zinnia species

Vegetables

• Squashes, Melons, Beans, Carrots, Corn

Fruit Trees

• Peach, Nectarine, Cherry, Plum

• Prunus species Pear-Pyrus species

Herbaceous Perennials

• Bugleweed, Ajuga reptans * Hollyhock, Alcea rosea * American Wood Anemone, Anemone quinquefolia * Jack-in-the-Pulpit, Arisaema triphyllum * European Wild Ginger, Asarum europaeum * Astilbe species * Bellflower, Campanula latifolia * **Chrysanthemum species (some) * Glory-of-the-Snow, Chionodoxa luciliae * Spring Beauty, Claytonia virginica * Crocus species * Dutchman's Breeches, Dicentra cucullaria * Leopard's-Bane, Doronicum species * Crested Wood Fern, Dryopteris cristata * Spanish Bluebell, Endymion hispanicus * Winter Aconite, Eranthis hyemalis * Snowdrop, Galanthus nivalis * Sweet Woodruff, Galium odoratum * Herb Robert, Geranium robertianum * Cranesbill, Geranium sanguineum * Grasses (most) Gramineae family * Jerusalem Artichoke, Helianthus tuberosus * Common Daylily, Hemerocallis 'Pluie de Feu' * Coral Bells, Heuchera x brizoides * Orange Hawkweed, Hieracium aurantiacum * Plantain-lily, Hosta fortunei 'Glauca' * Hosta lancifolia * Hosta marginata * Hosta undulata 'Variegata' * Common Hyacinth, Hyacinthus Orientalis 'City of Haarlem' * Virginia Waterleaf, Hydrophyllum virginianum * Siberian Iris, Iris sibirica * Balm, Monarda didyma * Wild Bergamot, M. fistulosa * Grape Hyacinth, Muscari botryoides * Sweet Cicely, Myrrhis odorata 'Yellow Cheerfulness,' 'Geranium,' 'Tete a Tete,' 'Sundial,' and 'February Gold' * Sundrops, Oenothera fruticosa * Senstitive Fern, Onoclea sensibilis * Cinnamon Fern, Osmunda cinnamomea * Peony, **Paeonia species (some) * Summer Phlox, Phlox paniculata * Mayapple, Podophyllum peltatum * Jacob's-Ladder, Polemonium reptans * Great Solomon's-Seal, Polygonatum commutatum * Polyanthus Primrose, Primula x polyantha * Lungwort, Pulmonaria species * Bloodroot, Sanguinaria canadensis * Siberian Squill, Scilla sibirica * Goldmoss Stonecrop, Sedum acre * Showy Sedum, Sedum spectabile * Lamb's-Ear, Stachys byzantina * Spiderwort, Tradescantia virginiana * Nodding Trillium, Trillium cernuum * White Wake-Robin, Trillium grandiflorum * Tulipa Darwin 'White Valcano' and 'Cum Laude,' Parrot 'Blue Parrot,' Greigii 'Toronto' * Big Merrybells, Uvularia grandiflora * Canada Violet, Viola canadensis * Horned Violet, Viola cornuta

• Woolly Blue Violet, Viola sororia

*These are based upon observations and not from clinical tests.

**Cultivars of some species may do poorly.

[SAS567]

At my previous home I used to have my veggie garden and raspberry patch close to 2 large black walnut trees and everything did fine. Sue in Mi. (zone 5)

[Stephen M. Henning]

The roots of Black Walnut (Juglans nigra L.) and Butternut (Juglans cinerea L.) produce a substance known as juglone (5-hydroxy-alphanapthaquinone). Persian (English or Carpathian) walnut trees are sometimes grafted onto black walnut rootstocks. Many plants such as tomato, potato, blackberry, blueberry, azalea, mountain laurel, rhododendron, red pine and apple 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 a 50 to 60 foot radius from the trunk, but can be up to 80 feet. The area affected extends outward each year as a tree enlarges. Young trees two to eight feet high can have a root diameter twice the height of the top of the tree, with susceptible plants dead within the root zone and dying at the margins. The juglone toxin occurs in the leaves, bark and wood of walnut, but these contain lower concentrations than in the roots. Juglone is poorly soluble in water and does not move very far in the soil. [from Ohio State University Extension Fact Sheet HYG-1148-93 by Richard C. Funt and Jane Martin]

At

the Ohio State University Extension and the American Horticultural Society have reported that R. nudiflorum, Pinxterbloom Azalea, and Exbury Azaleas Gibraltar and Balzac will grow near Black Walnut and Butternut trees. They also list many other plants that will grow in the root zone of these trees.

[figaro]

In New Jersey we had wild cherry trees and wild blackberries growing within

10 feet of some very large (40 ft. tall) wild black walnut trees along a fence row. This was 25 years ago so I can't remember anything else except that I had some hyacinths planted over my dead pet rabbit under one of the trees and they naturalized. Could you try experimenting with some seedling trees/shrubs to see what happens?

[Sis]

[Sis]

[Sis]

[Sis]