How long does black walnut toxin persist in the soil?
Paula_sfbay
21 years ago
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Hawkeye_Belle
21 years agoOkanagan
21 years agoRelated Discussions
black walnut tree killing spruce trees? help please.
Comments (5)Some trees will grow next to walnuts - see link below. I planted a few acres of walnut seedlings in one area of my reforestation project and used the list to determine which trees I could mix with the walnuts. I planted a lot of oaks, redbuds, and red cedars mixed in with the walnuts to add some variety, but several others will do fine next to them as well. Another option would be to remove the walnut tres and replant the spruces. I've read the juglone lasts 2-5 yrs in the roots/soil after the tree is killed so the new trees may get off to a slow start until the juglone totally fades away. john Here is a link that might be useful: Walnut Trees...See MoreBlack Walnut - Juglone and Rhododendrons
Comments (5)Some things that grow under black walnut are: Tolerant grasses Tall fescue and Kentucky bluegrass grow well near black walnut except during drought conditions when soil moisture is low. When moisture is adequate these grasses may grow better under walnut trees than in other parts of the lawn, possibly because the soil may be more basic. Soil under black walnuts tends to be alkaline, with the pH often 0 .7 points higher than beyond the roots, thus influencing the growth of many different plants. Tolerant trees and shrubs * arborvitae, American * ash, white * barberry * beech, American * birch, black; 'Heritage' river * boxelder * buckeye, Ohio * catalpa * cherry, black * crabapple * daphne * dogwood, flowering * elderberry * elm, American * forsythia * fringetree * goldenraintree * globeflower * gum, black * hawthorn * hemlock, Canadian * hibiscus * hickory * holly, American * honeylocust * honeysuckle, amur; tatarian * hydrangea * lilac * locust, black * maple, red; sugar; black; Japanese * ninebark * oak, white; red; scarlet * pawpaw * pear, callery * pine, Virginia * privet * red cedar, eastern * redbud, eastern * sassafrass * serviceberry * silverbell, Carolina * spruce, Norway * sumac * sweetgum * sycamore * tulip tree * viburnums (some species) * witchhazel Tolerant vines, ground covers and flowers * anemone * aster * astilbe * bee balm * begonia * bittersweet * calendula * clematis (virginsbower) * coral bells * creeper, Virginia * daffodil * daisy, shasta * daylily * evening primrose * fern * geraniums, hardy * goldenrod * grape, wild * hollyhock * hosta * hyacinth, grape; oriental * iris, siberian * ironweed * jack-in-the-pulpit * lamb's ear * liriope * lobelia * may apple * morning glory * mullein * phlox * primrose * raspberry, black * rose, wild * rudbeckia * scilla * sedum * speedwell * spiderwort * St. John's wort * sunflower * trillium * tulip * violet * wisteria * yarrow...See MoreReport: Black Walnut Rose Plantings
Comments (28)I have had the same issue with the native pecan trees, in Texas. The oak leaf hydrangea lasted three years. I love roses, but haven't tried them, yet. I didn't want liriope, but it moved in, and is doing quite well, much to my chagrin. But I have a thing about removing living things, so there they are! 😀 I've experimented with several native plants, and have found that yaupon, Turk's cap, (aka Mexican apple) does well, as do Christmas fern, St. John's wort, and artemisia. Daffodils, lily of the valley, and bearded iris have survived thirty years, with absolutely no help, as have the rosemary bushes. Oak trees, redbuds, and Eve's necklace have been next to the pecan trees, for thirty, to fifty years. Sadly, the mints, bee balm, and lemon balm only made it two years. On the upside, I've seen non-natives that have survived at least twenty-five years, such as Japanese boxwoods, nandinas, and ligustrums. The gardenia bush died within three months, even though I pampered it. Juglone is a real bugger, but the pecan tree is our state tree, the birds love them, and they provide a squirrel circus that is often hilarious! Loved your article, Hawkeye_Belle! I love roses so much, and I've spent thirty years wondering whether my pecan trees would do them in. You've provided some excellent information!...See MoreBlack Walnut as a Mulch
Comments (14)jon-you frame your comments in quotations, but don't specify who or what you are quoting. From what Steve and I have pointed out bw compost certainly is not benign to all plants, and can be rendered benign through appropriate composting practices. What is the point you are making? Sandy-many lists I have found show daffodils as tolerant, and I have also grown them successfully under bw. I plead ignorance in knowing the difference between daffodils and narcissus. I have also found lists that show that melons and squash can be grown under bw and that the fruits are not toxic to humans or animals. It seems the toxic juglone is not stored in the fruit or plant matter other than the bw debris itself. I will say that even the slightest trace of juglone spells death to tomatoes and peppers. I have grown Canna under bw. Most of the toxicisity of juglone, in the reports I have found comes from the roots and extend outward 1-1/2 times the height of the tree. So a 60 foot high bw intoxifies the soil in a 90 foot diamater circle from the trunk - roughly. This results in an area where many shade intolerant plants can exist.. That is why I made the comment that 'fringe' areas of a hosta bed under a bw can be useful for companion plants. My daylillies have done wonderful under bw, and the trees, in my humble opinion, are almost perfect 'dappled-shade' because of the lacy texture of the leafy fronds. The area under a bw is definitely NOT deep shade. Even the gentlest breeze allows direct sun to penetrate but not dominate. I have only gardened under bw, not intentionally used bw waste for mulch or compost. As Ken has pointed out, and the sources I have found support, leaching of juglone from surface debris doesn't penetrate far into the soil, but far enough to be toxic to seedlings of shallow rooted weeds and the plants themselves with shallow root systems such as tomatoes and peppers. The deep toxicity in soil comes from the bw root system. So to me, I don't have a fear of the thought of using surface applied bw debris as mulch or in composted applications for juglone tolerant plants. Theresa...See Morelisaloo
21 years agoLoriJean
21 years agoSusy
21 years agolisaloo
21 years ago
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