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lavender_lass

Walnut trees and roses...

lavender_lass
10 years ago

I've heard walnut trees and roses don't do well together...but how close do the walnut trees have to be, to cause a problem?

Is it 50', 100', 200' or 20'? Thanks in advance :)

Comments (14)

  • nikthegreek
    10 years ago

    I don't think that walnut trees go together with most other plants, due to walnut tree's allelopathic properties, although there are some tolerant ones. I would not plant a rose within its root zone, a radius more than the height of the mature tree to be on the safe side.
    Nik

    This post was edited by nikthegreek on Tue, Jan 28, 14 at 14:44

  • lavender_lass
    Original Author
    10 years ago

    Thank you. They're on property, not a yard, so they aren't that close, but I was wondering what would be safe.

  • rinaldo
    10 years ago

    It's deadly for any roses with china or tea ancestry. With others, it's hit or miss. I've got rosa mulliganii happily hanging from a black walnut and Chevy Chase only a few feet away. But I also once tried Commandant Beaupaire just outside the canopy of the tree only to see it die a lingering death. While the walnut roots are the real killers with the most concentration of juglone, it is lingers a while in the leaves to a lesser extent, so you would want to make sure you don't let them accumulate around plants or land in pots. Once they've composted they are fine of course.

  • jeannie2009
    10 years ago

    Hi Lavender, its good to see you posting.
    I cant remember if its black or English walnut; but one of them should not be planted near horses. Hope spring comes early for all of us.

  • seil zone 6b MI
    10 years ago

    I believe it's the Black Walnut that has poisonous roots. As long as the roses are planted out of the root zone they should be OK I think. My cousin has two Balck Walnuts in her front yard and has a very hard time getting anything else to grow there. However, she has a lot of roses in her back yard and they do fine.

  • nikthegreek
    10 years ago

    The document linked to below provides a list of plants supposedly tolerant.
    Nik

    Here is a link that might be useful: Black walnut allelopathy

  • cramoisi
    10 years ago

    Lavender,

    The English walnut/Black walnut distinction would disappear if the English walnut is grafted onto Black walnut rootstock, right? I have seen trees grafted precisely like this.

    Larry

  • nikthegreek
    10 years ago

    I'm not sure which walnut is common here in Greece but they sure exhibit these allelopathic properties. I suspect that many of the cultivated ones are of Californian origin, which would make them Junglans nigra (black walnut) cultivars I suppose.
    Nik

  • jeannie2009
    10 years ago

    The reason for my post, Lavender and I have horses. One of the walnut trees kills horses. I don't know which so I don't grow either. Just hoping to warn Lavender as horses are so special.
    Jeannie
    PS by the way...last spring I planted "Lavender Lassy", just thought you would want to know.
    Jeannie

  • floridarosez9 Morgan
    10 years ago

    Jeannie, it's black walnut.

  • lavender_lass
    Original Author
    10 years ago

    Jeannie- Thank you! I remember reading that now, when I was researching poisonous plants years back (first designing my garden). I wanted to avoid anything really bad for horses, cats or dogs.

    It says that the wood is bad for horses, when it's absorbed through their hooves...so not to use it for bedding. Falling walnuts can also be a problem, so no black walnut trees near the horses! I guess other walnuts can be grafted onto black walnut, so the roots can still be a problem for plants, too.

    Oh, those are supposed to have a nice fragrance! They're a little too cold sensitive for my area, but if we move closer to town...I do like the name! :)

    Jackie- Good to see your roses haven't suffered at all. I know every situation seems to be different...maybe it's the type of soil or how old the trees are, but I'm glad your roses are doing so well!

    Nik- Thank you for the link!

    Rinaldo- It always amazes me how different roses can be, depending on what type they are. It seems like the more I read about them, the more I realize I still don't know! I wonder if raised beds would help with vegetables?

    Seil- I read that lilacs and many other shrubs will do well with black walnuts...and it's a large yard with some property. The walnuts probably wouldn't be a problem, unless they're too close to the horses.

    Larry- I did see that and you're right...since the roots are the problem with the plants, it wouldn't make any difference if grafted onto a black walnut.

    Florida- Do you have any in your area?

  • floridarosez9 Morgan
    10 years ago

    No, we don't have them, but I'm always careful when I order bedding for the stalls. I make sure it's local and doesn't have any black walnut in it.

  • lavender_lass
    Original Author
    10 years ago

    You would think people would have more sense! It reminds me of the 'chocolate' mulch that some gardeners had around dogs :(