Planting query

[Mark Bolam]

That was part of my thinking behind choosing a different species for the replant mate, although we don't know if Sirrococcus was the culprit.

 

That and the customer wants a walnut.

[The avantgardener]

Black Walnut is less susceptible to Honey Fungus if this is the culprit.

[daltontrees]

Just be warned, Walnut is allelopathic i.e. it will try to kill all other plants within its rooting area. It usually does a pretty good job of this. It emits an enzyme called Juglandase that is toxic to most woody perennials as far as I can remember. Most trees are happy to share a rooting zone with other trees of another species, but Walnut wants it all for itself. I think it even kills its own offspring.

[Mick Dempsey]

Good factoid!

13 minutes ago, daltontrees said:

Just be warned, Walnut is allelopathic i.e. it will try to kill all other plants within its rooting area. It usually does a pretty good job of this. It emits an enzyme called Juglandase that is toxic to most woody perennials as far as I can remember. Most trees are happy to share a rooting zone with other trees of another species, but Walnut wants it all for itself. I think it even kills its own offspring.

I have a walnut in my field with an elder underneath.

 

lots of them hereabouts both cared for in gardens and abandoned, I will look around.

[Mark Bolam]

That’s fine, and a good factoid.

The bed the cedar is in is quite big, and has an understory of small hollies, but my rigging will kill them long before the walnut does....

[Mark Bolam]

Even if it doesn’t the grinder will.

[daltontrees]

I have stitched the following together frrm snippets found on reliable websites. I see that I remembered the toxic substance name wrong. It's Juglone, not Juglase. 5-hydroxy-1,4-naphthalenedione. But you all knew that anyway.

 

Seems English Walnut is not so bad as Black Walnut.  I think the latter only does well in UK in warmer areas. Walnus can struggle in Scotland, but bizarrely I found one doing well and fruiting on the very steep slopes below Stirling castle, on the most meagre of soils, almost bare rock. Judging by how hard it was to get to it to survey it, I think that brambles and nettles are very resistant to Juglone.

 

 

Many trees use allelopathy to protect their space by using their roots to pull more water from the soil so other plants cannot thrive. Some use their allelochemicals to inhibit germination or impede development of nearby plant life. Most allelopathic trees release these chemicals through their leaves, which are toxic once absorbed by other plants. Black walnut is a prime example of this. In addition to its leaves, black walnut trees store allelopathic properties within their buds, nut hulls, and roots. The chemical responsible for its toxicity, called Juglone, remains in the soil around the tree and is most potent at the drip line, though the roots can spread out well beyond this. The English walnut produces the chemical in lesser amounts.

 

Plants most susceptible to the black walnut’s toxicity include azaleas, pines, and birch trees.

 

Other trees that are known to exhibit allelopathic tendencies include maple, pine, and eucalyptus.

 

The tree of heaven, Ailanthus altissima, produces allelochemicals in its roots that inhibit the growth of many plants.

 

Ornamentals tolerant of walnut trees include forsythia, hawthorn, oaks, wild rose, daylilies, iris, phlox, Shasta daisy, and Virginia creeper.

 

Black walnut tolerant plants include the sugar maple, flowering dogwood and the boxelder to name a few. You can also plant crocuses, hyacinths and begonias. All of these plants are known to be black walnut tolerant plants. There are many more, and your local garden center can inform you of any intolerable plants so you don’t run into any problems.
 

Edited September 1, 2018 by daltontrees

[treeseer]

On 31/08/2018 at 05:14, Gary Prentice said:

Atlas cedar mark?

 

re. Replanting. If you’re replacing soil, it wouldn’t hurt to incorporate some nice mycorrhizal rich soil from a woodland/ mulch with cherry/hawthorn chip etc

Cherry/hawthorn good for fungistatic properties.  If the objective is good establishment of the walnut, then myco/soil from a walnut would be ideal.