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Juglone Walnut toxicity

Hello, I'm new to the forum and I'm in Bulgaria. I've been planting a small orchard but was unaware of the problems of planting near to walnut trees. Most of the information available refers to the American Black Walnut and I'm wondering if the European Walnut has the same level of toxicity. I've planted two apple tree about 40 feet away from a long-established Walnut tree. The trees that I've planted are 2/3 years old and neither are doing very well but I attributed this to the very dry summer and the stress of a four day car journey before planting. I could swap them with a cherry and / or a peach tree which I planted at a greater distance from the Walnut but I'd prefer not too. So, my question is, is 40 feet sufficient distance? And, are all cherry and peach trees unaffected by Juglone or is it just the wild cherry?  Thanks in advance to anyone who could help me with this


  • rachelQrtJHBjbrachelQrtJHBjb South BucksPosts: 370
    Allelopathy (or phtyo-toxicity) is more common with the Black Walnut. I would have thought that 40ft was more than enough and the issues you have encountered are most likely attributed to the stresses you say they have been subject too.

    This link from the RHS may help. but there's very detailed information online if you search allelopathy and walnuts.
  • Ok, thank you, that's re-assuring. I was setting aside a part of today to swap the one of the cherry trees with the apple but perhaps I'll give it til next spring when I come back here and see how they've coped over winter
  • KeenOnGreenKeenOnGreen Posts: 1,068
    We have various plants that are within 1 - 2 metres of our English Walnut (Juglans Regia).  We also planted some perennials around the base of the tree.  None of them have been affected at all. 
  • DovefromaboveDovefromabove Central Norfolk UKPosts: 64,519
    There was a large English walnut in the corner of the veg garden on the farm where I grew up. Apart from immediately beneath its canopy (where nothing was planted anyway) everything grew perfectly well. 
    “I am not lost, for I know where I am. But however, where I am may be lost.” Winnie the Pooh

  • Butterfly66Butterfly66 BirminghamPosts: 391
    Lots of stuff grows quite happily under our walnut, right up to and around the trunk. We also have a cherry and growing less than three metres away ( too close but we didn’t plant it)
     If you have a garden and a library, you have everything you need.”—Marcus Tullius Cicero
  • Thanks to all of you for your help, it's very much appreciated. I was getting information from the internet and a lot of this was related to American Black Walnut which seems to be problematic for most plants that haven't co-evolved. I made the false assumption that this would also be the case with Juglans regia  
  • KeenOnGreenKeenOnGreen Posts: 1,068
    To illustrate the point, here is some Arabis living quite happily right up to the trunk of our tree.

  • That's interesting. I believe Arabis is a Brassica which is one of the types of plant that are definitely not recommended to plant anywhere in the vicinity of Black Walnut so it seems that since yours are doing fine planted next to European Walnut.
  • KeenOnGreenKeenOnGreen Posts: 1,068
    Well I never knew Arabis was part of the Brassica family, how bizarre.  It flourished under our Walnut tree, but we actually got rid of it last year.  An invasive form of Oxalis kept self-seeding itself in amongst the Arabis, and it was impossibly to get rid of it, as the Arabis was so densely matted.  A shame, as it looked great around the tree.
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