And he was recommending that if you have black walnut trees and apple trees… if you will plant some other juglone tolerant trees in between (to form a barrier - to protect the apple trees)… he seemed to think that would help. He has a book he is showing, where mulberries were mentioned as one of those juglone tolerant trees that would help, and from his experience so would pear, saskatoon and plum.
so if you have Black Walnut… then… Apple tree…
when the Black Walnuts get stressed… your Apple tree is a goner.
But if you have Black walnut… (mulberry, saskatoon, pear, plum) — then Apple Tree and the distance from the Black Walnut to the Apple tree is the same as above… the Apple Tree will be just fine.
The mulberry, saskatoon, pear, plum ---- act as a barrier.
Alan… just a guess… but perhaps black walnut tree roots (and probably all tree roots)… are smart enough to put energy into expanding into areas with less competition… and less energy going into locations already crowded with other tree roots… especially when those other tree roots are juglone tollerant.
Interesting theory… Around here I know that if a Beech tree grows large it’s rare for anything to continue to live or thrive in or around it’s understory. I’ve always just assumed the mass of near-surface roots they have suck up all available moisture/nutrients. Perhaps Walnuts do similar…
Building on the above, there is a lot of suggestion that myccorhiza and assorted other beneficial bacteria can break down juglone faster. A lot of trees develope relationships with such bacteria and increase its presence. The community aspect involves sharing of nutrients and resources across that mushroom mat.
Why I’m prodding the thread though, is that I am curious if anyone has gotten further with whether or not Jujube is juglone sensitive or not. As well as reasking the question of whether tolerant rootstocks offer protection to less tolerant scion in this situation (for any edible crops).
New questions are whether or not flowering quinces, pseudocydonia, or yellowhorn have been observed to be affected as of yet?
I’ve removed a number of black walnut saplings from my yard that the squirrels were less scrupulous about locating htan I would have been. I still have some trees I intend to keep, and will suffer the length of time for some of the root systems to die back in some areas before I can plant what I wish in those plots, but I suspect some of my potted trees likely to be planted out in the next year won’t really have a care about those roots continuing to shed juglone for a few years.
There were several statements about BW suckering or sening up shoots further away above. I have never experienced this. My suspicion is that squirrels secreted them and found easier meals before they came back for them, but if anyone can state difinitely that the sucker propagation occurs, I’d appreciate more detail. The place where I work gets volunteer BW, Butternut and assorted hybrids all the time, and there is not a tree visible anywhere in the neighborhood that I can spot. I’m fairly certain they are imported by wildlife, so I know they will carry them quite a distance sometimes.
Just ran across this thread, luckily. I have two big black walnuts I didn’t cut when clearing my “backwoods orchard” plot. I was planning planting apples around them in the spring. How close can I reasonably plant near the BW? I will fill the space with persimmons.
It is a bit different with European regia walnut, but here are my observations:
We have huge trees all over our property with the exception of a 90x20m portion of food forest dedicated to mostly apples, apricots and fruit bushes that would do poorly in drought and shade. We leave hulls and leaves under our walnuts most years.
walnuts do dry the ground so that even drught&shade tolerant undergrowth will die during a dry spell.
their roots may extend far beyond the canopy line. We’ve dug into 5cm thick ones 3m from the branches and tiny ones further away.
an apple tree will do just fine (maybe grow a little slower) if planted close enough to a walnut for the canopies to touch, if either of them is in a wet spot. The apple may suffer in extreme dry spells just like any other under extreme dry heat.
drought tolerant/resistant ornamental and fruit trees /bushes seem to do well around walnuts if not under the canopy. This works for thick leaved trees like mulberries or trees with deep roots. Or for otherwise highly competitive trees like prunus.
walnuts make the darkest shade of all our trees and stop air movement around them (maybe huge morus nigra are better at both?)
same issues as with walnuts arise around huge cherry trees and european ash. I think they just have the brute force to take all they need, casualities be dmned.
I can’t imagine how a 'tolerant’species barrier would work unless the walnut would literally take that tree’s roots as a war frontline and not extend its roots much beyond that. I need to see that dug up somewhere. I’m not good at beliefs…
Steffan at Miracle Farms has a youtube vid on walnuts near fruit trees that is good.
He planted several feuit trees near black walnut… and they did just fine for many years…
Until… he had a very dry season… then the apples, pears near the BW all srarted dieing.
It seems that the BW will tolerate many other trees in their root zone… as long as times are good and resources… water, nutrients are plenty…
But when they get stressed… they can bump up the jugulone and take out the competition to ensure their survival.
He also noticed that some apple trees survived being close to the BW… when there were other trees like mulberry planted between the BW and the apple tree.
It was like the mass of roots from the mulberry ran some type of interference… and that protected the apple tree.
Perhaps BW roots simply will not go out as far in a direction that they find a mass of other roots already established in.
It was a good vid… i have no BW here on my place… lots of hickory but no BW.
When I first started planting my apple trees I didn’t realize the BW jugulone poisoning. The apple trees near the BW trees are dead/nearly-dead. I am reserving those locations for persimmons now who I am given to understand are not affected.
Tana, Juglans regia produces about 20% as much juglone as Juglans nigra. While your experience with regia is typical, ansayree has nigra. I don’t know if persimmon is tolerant of juglone… and I know most of the susceptible trees. Ansayre, black walnut roots are typically twice as far from the tree as the canopy is tall. If the tree is 50 feet, walnut roots will be 100 feet from the trunk. Apples are 100% affected, particularly from the leaves and also from the roots. I’ll look up persimmon and see if I can find anything showing it is either susceptible or tolerant.
Thanks. My BW are 60-80’ tall, but the canopies obviously aren’t that wide. Couldn’t bring myself to cut them when I was clearing. Seemed like a horrible waste for them to be used as firewood (I save BW, oaks, hickories, persimmons and sugar maples). I might regret that decision.
Trevor, thanks for pointing out mulberry compatibility. I have an IE and a couple of red’s that need a home next year.
I saw a youtube by strudledog a few years back and he has a CHE growing quite close to a large BW… and it was doing well and producing nice size fruits.
I understand that. If I remember well, Stefan Sobkowiak advises against all juglans. He has sandy soil and I wonder if the type of soil may be one of the bigger factors : permeability of soil + availability of water and nutrients+ allelopathic potential of the tree. Could that be why the reports differ? Btw, we have a similar issue with fraxinus excelsior. (not because it’s likely to come down crashing.).
@TNHunter I don’t think it is so much that the tree produces more juglone as more of what is in the soil gets turned into juglone. The trees primarily create a precursor to juglone that will become juglone upon aeration. More dry time = more conversion. There are a couple bacteria that break it down faster, but it essentially gets broken down again from the juglone phase to more neutral compounds.
To complicate things. J nigra is also expected to produce multiple allelopathic compounds which different plants will react differently to. Juglone is simply the one they have been able to study fairly thoroughly.