Good observation it seems accurate to me. In old growth forests, trees can be highly toxic. I became exceedingly ill once after being in some old growth forest. My grandmother asked where i was specifically. I was in a particularly toxic part of the cedar woods. They were being encroached on by black walnut and oaks. My grandparents said both types of trees were more toxic than normal because of their long-term relationship together. Neither species of trees giving an inch to the other type. Nature in harmony or at war, depending on how you view it. Pawpaw grows all along the waters in that location. Those cedars were so toxic it left me covered in a miserable oozing rash well over 2 weeks from walking through there. The only thing there were cedars and were holding their own against huge 100-foot and taller walnuts and oaks. To see old growth woods untouched by anything for at least a hundred years is a big privilege. My families private property is unique in that way. Many trees are hundreds of years old. The toxicity of that place is very high for any living thing. Crossing into a section means there is always a dominant species. In the case of those cedars, there is sometimes 20 or 30 feet between trees, but everything is dead besides them. Literally no grass, no brush of any kind, no poison oak or ivy just them. That is what made it such easy walking there, which was my mistake. Nothing but cedars grow there, and they have pawpaw lining the creek in front of them. Walnuts mixed with oak, hickory, and butternuts to the sides. The only one foreign invader i saw that snuck in under walnuts was multiflora roses. They seem to be immune to all alleopathy besides those cedars. My grandmother mentioned those cedars are reduced in height, significantly never growing very tall. In my area, a cedar could become huge, but not there 15 feet tall is a big one. Cedars in my area allow other trees to grow amongst them. They also cause me no allergic reaction. The cedars on my grandparents’ property had made me more ill than i have ever been. It feels like fire on my skin. It spread like poison ivy does on some people. Had poison ivy in one spot once after mowing off a 1/4 acre of it. A large glob of the stems and leaves clogged the riding mower, and when it came out, the juicy clump smacked me in the back one fall. It left a patch on my skin about 2×3 inches but didn’t spread at all. It reminded me of what those cedars did to my entire body by walking through there. My long-winded point here is that some trees are genetically pre dispositioned through natural evolution to have higher toxity than others in their same species. Not all walnuts are as toxic as others. Most trees are as toxic as they need to be. Orange trumpet vine can be toxic to certain people.
If you want apples, you probably need malus coronaria rootstock. Several years ago I top worked a few wild ones that were within 10 feet of BW, and they are now producing.
Many of the ornamental cherries have other prunus genetics mixed in. Some like nanking aren’t really even cherries, and are quite sensitive to BW.
The title of the PDF is a bit of a misnomer. Look at the table survey of forest trees/vegetation found in natural proximity to BW.
Effect of black walnut trees and their products on other vegetati.pdf (2.4 MB)
Agreed. I just need to find some callery that’s grown in natural proximity to BW. If you ever have spare, I’ll happily take some.
Yes it contains juglone…the question is, is it a high enough dose to kill things (other than the most sensitive nightshade plants)??
Since there is a focus here, i’ll reask a couple I’ve dropped in at various points, and probably a couple extra I haven’t.
Any experience here with BW in proximity to Franklinia, Yellowhorn, Seaberry, S domestica or S. Torminalis?
Is their alleopathy likely to affect their cousins a la English walnut and thh like?
The squirrels on my property have a different plan than mine. I’m constantly ripping out seedlings in areas of the yard where they would cause future damage. I love my adult tree, and it is in a great spot. My neighbor is happy to have me plant on a plot of land that is technically his, but looks like mine. He unfortunately wants one of the volunteers to be left where it is, which means most of what I want to plant won’t be going there. It’s been run over so many times there won’t be any digging it up, but it now has a nice array of branches that means I’m going to enjoy looking at it.
more unfortunate is that there is a section of land that is vague as to whether it is mine, another neighbors, or dependent upon where the creek in the middle of it decides to be from year to year. It is always soft and damp, and the squirrels have been tending it since well before I moved here. At least one of the BWs they have cultivated is now old enough to bear fruit. I can minimize how many nuts they have access to on my grandmother tree, but I can’t really get to this tree and as it grows, more and more of the nuts will fall into the neighbors pasture and land that is soft enough that the falling nuts will bury themselves. I’ll be finding more and more volunteer BWs in the coming years. I wish I could sterilize them somehow so that they could be beautiful without contributing fodder. They are thankfully in a spot where their own juglone won’t ever be a problem.
I haven’t any experiences with those species at the old orchard that had the black walnuts everywhere.
We have most of those here at the new orchard but there are no black walnuts here (I made sure of that in year 1)
I can’t comment on the other species, but all walnut family members produce some amount of juglone and are therefore immune to the effects. Even pecan has a small amount
I think the effects are highly tree and site dependent. I had a big (trunk more than 2’ across) black walnut tree in the middle of my yard, which grew 35’ from a sour cherry (trunk probably 2’across), about 30’ from a healthy callery pear, and about 25’ from a mature hackberry tree. However, I live in a bit of a low wind pocket that probably restricted movement of BW leaf litter and none of the trees were under the BW canopy, though the hackberry was very close.
I just had that black walnut and another one nearby cut down. I guess I should trial some tomatoes around the area before putting in anything sensitive. Or I could just install a persimmon, pawpaw, chestnut, and witchhazel wilderness over that area.
Sounds to me like you should be collecting nuts for yourself instead of letting the squirrels get 'em all.
I think your Franklinia is close enough to magnolia to be risky. (It’s hard to raise in the best of circumstances, much less near the juglans nigra.) Hickory, pecan, English nut trees should be OK.
I have butternut, an English ambassador walnut grafted on paradox and 2 pecans. It will be interesting to see how they interact with other plants.
I pick up the ones on my sentinel tree near daily and sometimes more than once a day when I’m not working, but hte ones on the neighbor’s property and in the no man’s land are rather difficult to get to when they are dropping. If they’d drop in February…