Hey Folks.
There are a few walnut trees at one end of my garden.
My dad always thought that the trees, (roots) somehow poisoned the soil nearby.
Even if the tree is cut down, do the roots live on and continue to contaminate the ground ?
Seems very few things grow well directly under them, like wild raspberries, but my tilled ground is 20' or more from the base.
I'd hate to cut them down, but will if necessary.
And, how to kill the stump and roots ? How long before there are no remnants to affect the crops ?
Thanks !

I know you cant grow garlic near most any nut trees.But I don't have an answer to your problem.

You are talking about juglone toxicity.
,
Some people think that walnuts can concentrate iodine from soil, which they do, and that it's the iodine vapors they emit that kill the herbs underneath (especially when green nuts fall down and grass dies around them). In reality it's the juglone, which just happens to smell similar to iodine. It's the same substance that gives walnut hulls their dyeing properties. It's said to degrade in the soil/compost within 6 months.

Allelopathy is a common biological phenomenon by which one organism produces biochemicals that influence the growth, survival, development, and reproduction of other organisms. These biochemicals are known as allelochemicals and have beneficial or detrimental effects on target organisms.

Nothing grows well in the shade.

Like previously mentioned walnut trees produce juglone which can harm other plants around the tree. Although I’ve seen plenty of stuff growing around walnuts I can’t imagine it be good for a garden. If you’re not have issues I probably wouldn’t worry to much about it.

I haven’t heard of other nut trees like hickory’s being allelopathic but walnuts and hickory’s are in the same family (Juglandaceae) so I wouldn’t be to surprised if they did as well

I planted 26 tame blackberries about the drip line and out past the drip line. There are several walnuts are in that tree line. All the Blackberrys were dead in 2 years. Was it the walnuts? Now I don't plant near them.

Very interesting, thanks !
Years back I ran a sub-soiler to break up the ancient hardpan and snagged some roots, 20' from the tree.
They were nasty, slimy bleeding, similar to the hulls on the nut.
I suppose there was a bit of that juglone there as well. But, that wouldn't likely be a problem till they were wounded ... or maybe when the tree was killed.

Thanks again,

Not only does a Walnut keep other plants from growing under and near them, the wood chips, bark and nut hulls are toxic to many animals especially Horses, and the husk's will kill fish if it get's in the water.

I worked with a guy when I did line clearance tree trimming that would get burns on his skin if he cut walnuts.

Black walnut dust, from woodworking, makes me noxious, if I don't wear a mask. I like to eat black walnuts, especially in chocolate brownies and have no problems from eating them.

Two of my uncles, when they were kids, figured out they could use walnut branches, with leaves, to stun fish. They were beating the water with walnut branches, to drive fish into a net and the fish started to float up. Later on, they would poison small pools in creeks and collect the fish at the downstream end, after they were stunned by the juglone.

Keith

Something else to consider about black walnuts is that they are poisonous to animals like dogs and horses. If they eat the bark, leaves or nut's it will cause paralysis. My three Labs were running around with and chewing pieces of BW I cut for firewood as Labs will do. The next morning none of them could walk, their rear ends were paralyzed. I called the Vet and he said to have them drink a lot of fluids and it should flush through their system. It worked and by the evening they were much better. Just a FYI.

Very interesting

deer and walnut trees is why we don't have our garden anymore

Walnut trees and their nuts as well as their leaves are toxic to Horses and that is why they bare no where near my pastures. My Pastures are very lush and heavy Fertilized but I know that Walnut Trees will kill the grass as well as the Horses.

I know walnut trees are hard on some plants, but I've never seen them kill grass.

Always had good grass on the lawn under walnut trees. But NO weeds.

I have 2 pretty decent size walnut trees in my yard and there is plenty of grass and weeds that grow under them just fine, I don’t have vegetables or flowers under them but haven’t seen any negative effects on the grass with the exception of when all the nuts fall I have the kiddos put them in a pile and it will kill the grass once they start decomposing now I’m not sure if that is due to the husks and nuts or due to the fact that the area doesn’t get much sunlight I’m not a scientist but if you don’t have problems now with your garden I would leave em if you do I would personally move the garden before I cut down trees but do what ya want pretty sure if you cut em down you can take some copper nails and drive em into the stump all around and it should kill it in a couple years if you want it done sooner rent a stump grinder, grind them all down then dig down to remove the chips until you get to dirt and refill the hole with new dirt. It might not be copper nails I don’t personally remember but I know my dad killed some trees growing up like that. Good luck…. Edit if it’s a big tree you will need multiple nails also if you cut it down take the stump and drill multiple inch and half or 2 inch holes in it and you can fill em up with gas multiple times and it will kill it off.