Are walnut shells bad in soil ?

[Mike123]

I have large walnut tree that is near my benches.and the squirrels eat the walnuts and eat the casing around the walnuts and they fall from the tree and land In the pots. Wasn't sure if it's toxic.

 

[Cadillactaste]

Depends on if they are juglone tolerant I would think.http://www.greenwoodnursery.com/page.cfm/109995

---

 

[Mike123]

Thanks, but I'm not sure it's a black walnut, I have in my collection boxwood, barberry, juniper, yew, and mugo pine. I pick out what I can just in case.

 

[Cadillactaste]

*All species of the walnut family produce juglone. *Black walnuts have the highest concentrations. Relatively small amounts are found in butternut, hickory, and pecan. Most toxicity problems are caused by the black walnut.

http://lancaster.unl.edu/hort/articles/2003/juglone.shtml

 

[Dav4]

I wouldn't think a piece of walnut shell here or there in a pot would be that toxic. I would just pick them out as I see them which is what you're doing ...Problem solved.

 

[Mike123]

Ok wasn't sure, I'll keep picking out. Thanks.

 

[Cadillactaste]

I would only be concerned if the outer shell also there. Removing debris and be watchful of it showing signs of decline. We lost much landscaping materials from not knowing. You may have one juglone tolerant. I would look that up. You may not even need to concern yourself.

 

[GrimLore]

Juglone is mainly produced by the roots of the Black Walnut and many trees and plants cannot be planted in the root zone as it will kill them. There is of course lesser amounts in the leaves, bark, wood, and seeds and they can be safely composted because the toxin breaks down during the process. I myself would not worry about the fruit but would not let it sprout.

Grimmy

 

[Cadillactaste]

There are different times durning the year, that the hull around the nut can be a strong carrier of juglone. Yes...the roots play a HUGE factor with juglone. But...the hulls of the walnut can wreak havoc in planters. I asked about putting a planter under our walnut tree years back and was told to be watchful of the hull casings that the nuts are in. Being contained to a container would allow it to build up juglone at a higher rate if not watchful. After the year of planting and having everything die. I opted not to put a planter there. Just didn't wish to lose more plants.

In addition to the fruit, juglone has also been found in the leaves, branches, and roots. The actual concentration in each part varies with the season. In spring, juglone is concentrated in the rapidly growing leaves. The amount of juglone in the roots remains relatively high throughout the summer. The concentration of juglone in the hulls of the fruit increases as the crop matures. All species of the walnut family produce juglone. Black walnuts have the highest concentrations. Relatively small amounts are found in butternut, hickory, and pecan. Most toxicity problems are caused by the black walnut.

http://lancaster.unl.edu/hort/articles/2003/juglone.shtml

I would think as long as you are not letting it break down into the soil...and removing all signs of walnut you should be okay. Just letting it compost in the pot would be not good. Unless It's juglone tolerant...then, I wouldn't worry about it in the least. It pays to know what plants are though. You may not need to worry about being as diligent with some.