Sunday, 27 September 2015

Plants That Can be Grown Around Walnuts and Hickories - Juglone Tolerant Plants

Plants Tolerant to Juglone


Walnuts and hickories produce the chemical juglone, which is exuded from all parts of the plant. This chemical can inhibit the growth rate of nearby plants, a phenomenon known as negative alleopathy.

 
The following lists of plants tolerant to juglone were compiled from published sources. They are based on observation under various settings, but few plants have been experimentally tested for sensitivity to juglone. The plants highlighted in green are species I have personally observed growing seemingly unhindered in and around the under story of Juglans regia.

Walnuts from our Gardens  
Many factors affect sensitivity, including level of contact, health of the plant, soil environment, and the overall site conditions. Aside from juglone, a mature walnut will cast a very heavy shade and young sun demanding plants will not survive in these conditions. The lists provided here are strictly guides and cannot be considered complete or definitive.

20 yr old Walnut in our Garden  with Sambucus nigra, Aronia melanocarpa and Pyrus cv. doing very well 


If you have experience of plants growing well under and around a Juglone producing plant that are not on this list, please share in the comments section below.

View our previous post for The Essential Guide to Everything you Need to Know about Walnuts!.






Bulgarian Walnut Cultivars - Hardy and Resistant to Major Pest and Diseases 


Below you can find profiles of some Bulgarian cultivars that we have on offer at our Bio-nursery. These cultivars  are high yielding and resistant to common walnut diseases. 

We are currently offering these cultivars at ​​ €22 per tree with 10% discount for orders over 10 trees. Delivery all other Europe

For other disease resistant walnut cultivars see Agroforestry Research Trust.

Walnut cultivars for Permaculture and Forest Gardens 


Cultivar - 'Izvor 10'

  • Fruiting - The fruit forms on lateral buds and ripen around mid September. Excellent tasting oblong nuts with a thin shell. The nuts weigh around 10 g have a high fat content - 55.7%.
  • Disease Resistance - Excellent resistance to Walnut anthracnose and Walnut blight
  • Form - The tree forms a broad, relatively thin crown
  • Hardiness - A very hardy cultivar tolerating temperatures down to -25 - 30 ºС
  • Flowering Period - Late

Cultivar - 'Sheinovo'

  • Fruiting - The fruit forms on the tips and ripen around mid September. Excellent tasting nuts that are easy to remove from the thin shell. The nuts weigh around 12 -13 g and have a high fat content - 71.4% . 
  • Disease Resistance - Good resistance to Walnut anthracnose and Walnut blight 
  • Form - The tree is vigorous with a wide spread crown 
  • Hardiness - A hardy cultivar tolerating temperatures down to -24 ºС 
  • Flowering Period - Mid - Late

Cultivar - 'Dryanovo'


  • Fruiting - Fruits for on the tips of branches and ripen to very large 14 - 18 g round nuts. The fat content is 67.39%. 
  • Disease Resistance - Very resistant to anthracnose, though very susceptible to blight. 
  • Form - The tree is vigorous with dome shaped crown 
  • Hardiness - A hardy cultivar tolerating temperatures down to -24 ºС 
  • Flowering Period - Mid - Late

To order some walnut cultivars for delivery this winter contact us at balkanecologyproject@gmail.com


Keeping  in touch 


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We offer a range of plants and seeds for permaculture and forest gardens from our plant nursery including a new range of fruit and nut cultivars well suited to natural gardens. Delivery to all over Europe available from Nov - March 


 Balkan Ecology Project Bio-Nursery 


 References 

  • http://extension.psu.edu/plants/gardening/fact-sheets/trees-shrubs/landscaping-and-gardening-around-walnuts-and-other-juglone-producing-plants




5 comments:

  1. Hey Paul! I know several sources state asparagus is not juglone tolerant, however I've seen them planted "under" a walnut tree and growing strong. They were planted at about 3 m from the trunk, still within the dripline of the tree (huge old walnut).

    A few years agore we planted about 15 1-year old crowns near a walnut in an unused yard and those fared really well, considering we did not water them at all for 2 years and in high summer they were totally out-competed by other weeds.

    Last autumn we took those out and moved them to another garden, but my conclusion is that asparagus is at least a bit juglone tolerant.

    In the same unused yard we planted test beds of potatoes and it was a really cool demonstration - the leaf mass of the potatoes formed something like a gradient away from the walnut. Those nearest had small and few stems/leaves, while those farthest away (15+ m) were developing normally.

    Cheers!

    ReplyDelete
  2. Hi Bobi

    Thanks for sharing that. Were the potatoes you mentioned receiving around the same hours of sunlight?. I've added Asparagus to the list.

    Cheers

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  3. Yes, the potatoes were in the shadow of the walnut before noon. There must've been some small advantage sun-wise for the ones furthest from the tree, but I don't believe a few minutes justify such a dramatic difference.

    Sadly , we were not able to compare yield, as an industrious mole-rat (сляпо куче) gathered almost all potatoes before us!

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  4. in Greece the most commonly found flower under walnut trees is vinca major (lovely blue-purple flowers, very hardy, can become 'weeds'...)

    ReplyDelete
    Replies
    1. Hi Ξωτικό

      Thanks for that, I'll add that to the list. I'll try planting a patch of Vinca spp. around a walnut in our garden. I find they make great carefree ground cover that can cope with a little trampling and provide a valuable source of early nectar/pollen for bees.

      Cheers

      Delete