I am horticulturist and find. Myself stumped. A self-sewn black walnut is straddling my neighbors fenceline. Growing up it is an old tea rose in my yard. Its been there longer than the wanut and is healthy. Within 2 feet of the tree trunk is a 20 year old baptisia also healthy. On the other side a 15 year old Japanese lilac. Most strange is a healthy self-seeded tomato within 6-8 feet.
The walnut first fruited last year. I was careful to pick up all fallen fruit and !eaves.
What do you make of this?

Hi Denise, to NGA

I'm looking forward to hearing more from you. It sounds like, with your background, you have a lot to add to NGA.

Black walnuts: That's a good question. My only thought is that the walnut is not big enough yet to cause problems but its only a matter of time. Every one of those plants should be unhappy so close to the walnut tree. You are minimizing the damage by keeping the leaves and nuts cleaned up but the root system is still down there doing its black walnut thing. Will your neighbor consider taking the tree down? Too bad they let it grow there in the first place.

Just a few ideas that come to mind here - first, I wonder if the black walnut tree needs to be more mature to start secreting the alleopathic agent (juglone) through its roots. Maybe you've prevented it from spreading the stuff around by picking up the leaves and fruit, but I'm pretty sure they also secret the stuff from their roots. Second idea, it's possible that your three other mature plants, the rose, baptisia and lilac have deep enough roots that they haven't been affected by the walnut tree yet. No idea about the tomato, but there are some plants that are tolerant of growing near black walnuts.

Unless you're able to talk your neighbor into having the tree removed, I think your only options are to keep doing what you're doing, picking up the "droppings" and to prune the tree as much as you can on your side of the property line and cut off the flowers, too. They also have the juglone in them.

Here's a good article I found, with a list of plants tolerant of juglone: http://www.mortonarb.org/trees... It specifically says that baptisia is NOT tolerant, so if you can't remove the tree, I'd think about moving that plant asap. It also says that tomatoes are not tolerant, too . . . so this again indicates that the roots of your tree aren't affecting the soil much - at least not yet.

Wouldn't your climbing rose also be a lot happier growing in more sun? The tree must be shading it quite a bit. Very hard to move an old, established one like that, but maybe think of starting some cuttings of it in case the walnut does poison it down the road. It may be an "own root" rose in which case the cuttings will come true to the original plant.

My first thought was...are you sure it's a walnut and not a black locust? Locust deposit themselves in the middle of anything.

What did the fruit look like from the tree?

I don't think this would be a project for pick-and-shovel, more like power digging tools. And it might get your neighbors REALLY mad at you, if they value the tree. But if they value a tree that will become huge, and that kills other plants, why plant it 49% in a neighbor's yard?

But you COULD dig down very deep on your side of the fence and install metal flashing or some REALLY thick and strong plastic barrier. Possibly, as with bamboo, pour some concrete. Force any tree roots that want to live on your side of the fence to go down 4-6 feet before crossing over into your yard.

Maybe they won't grow back up to the surface. If you can keep those tree roots below your root zone, maybe the juglone won't poison your plants.

But if there are already many tree roots on your side, cutting them will hurt the tree, and it would be visible.

Sounds to me.😕😒😄..That they all like where dars growin #!!! 😎 I'm hear in the middle of Californias central valley.Aug23.
I got two volenter tomato plants.came up a few weeks.about 3 inches tall.I'm gonna put em in pots.And when time comes 4 cold or frost put em on patio.so they will be protected . then when safe next yr. Put em in garden ! I'll have tomatoes before people are buying there plants #!!!!
Hummm!!! I just might mark where they were and put em back where day came from!!!😎 ALSO!!!! There are certain spots in my garden where certain veges grow better ???? I dont know why maybe you do ? Garden is approx. 20× 35 feet with 150 feet of drip line. I've been gardening 35+yrs. Nature is a trip. And MAGICAL!
SO SMILE !!! 😎😎😎

Philipwonel said: ... ALSO!!!! There are certain spots in my garden where certain veges grow better ???? I dont know why maybe you do ? Garden is approx. 20× 35 feet with 150 feet of drip line. ....

Well, sun is a huge factor. Maybe some plants need afternoon shade, or are actually cool weather plants.
Most veggies need "full sun", but maybe "full sun" in Fresno California is too much for some.


If you haven't tilled deeply in decades, maybe your soil varies from spot to spot. If you fertilize one row at a time, maybe some areas have too much of some nutrients (N is particularly toxic when in excess) or not enough (heavy feeding crops can suck the fertility right out of some soils).

You might try wheelbarrow-ing some soil from some spots to others, to average the soil out and make a level surface. Then get a soil test.

But my answer to most gardening questions is "Drainage!" After a rain, do you have patches of soil that stay soggy longer than other patches?

Do low spots flood or hold puddles more than briefly? A few inches above or below grade could make a big difference if your drainage is marginal. If soggy soil is an issue, you could mound up soil in the rows, pulling soil from the walkways between rows, to make slightly raised beds.

(But I think you said "drip irrigation", which hints at dry soil, so don't park your roots zones any farther above the water table than necessary. If the drip irrigation might be variable, consider replacing drippers in the bad spots, or start buying pressure-compensating drippers.)

Or, if your soil is sandy (excessive drainage, insufficient water-holding-capacity), patches with better soil would have a big beneficial effect on crops. Add even more compost than you do now! Mulch heavily, because that's future compost and today's evaporation-reduction. Can you get your hands on large amounts of less-sandy soil, to amend your garden?

Rick we're talking California there . . they haven't had enough rain to make a puddle in years, right?

Philip, got any black walnut trees near your garden? You write with a Bahamian accent.

Just read what others said while i was writing you. They are right. There is not much that grows under any tree . except 😬WEEDS # 😬
Hear in Fresno. By law. You can cut anything encroaching over your property line.straight up an down. I hope the tree isn't limiting the light to your garden.
Also . The neighbors may of not planted the tree ! And if they did. Not of known the affects it would cause to you !
😎😎😎

Fergusmom said:self-sewn black walnut is straddling my neighbors fence line.

This is not a horticultural answer...it's more of a legal one. Have you had the property surveyed and do you know exactly where the property line is? Many times people erect a fence not exactly on the property line; hopefully you will learn that the tree is yours. When I paid the surveyor to make the 4 corners my yard suddenly got 4 feet larger along one side; the neighbors fence is nowhere near the actual line.

Good luck and hope everything works out.

No, no puddles in Fresno. In fact, it might be a lack of water that is troubling Phillip's garden.

Phillip, 150 feet of drip line? I hope you have good water pressure. You sure its water flowing down that dripline - might be sand by the end? I thought you were speaking Hawaiian Pidgin. You sound just like my cousins. Its August 23 at my house too. We must be in the same time zone.

Rick, yes, if it ever rains in California again, Phillip will have puddles as the entire central valley is a block of hardpan.

Alyssa, Denise is a horticulturalist and a Master Gardener. She probably can tell the difference between a walnut and a locust.

AlyssaBlue said:My first thought was...are you sure it's a walnut and not a black locust? Locust deposit themselves in the middle of anything.

What did the fruit look like from the tree?

Thank you. Yes its a walnut. The fruit llooks like fuzzy yellow baseballs. Its over 20 feet tall-grew terrifically fast. The fruit also has that pungent petrol smell.

Fuzzy yellow baseballs? Not hard green golf balls?

Notech said:
The fruit llooks like fuzzy yellow baseballs.

@ Notech, are you talking about the tree encroaching on the yard of @Fergusmom's?
? Black Walnut would not be fuzzy yellow balls, they look like this:



Please, where is your tree growing and can you upload images so we can take a look?

This thread is a little confusing. Is Denise answering that it is definitely a walnut tree?

Denise, horticulturalist and Master Gardener says her tree is a black walnut.

Notech, no credentials, says yes, his is a black walnut that has fuzzy yellow baseballs.

Got it?

PS: Notech. Maybe you can start a new thread and post some photos of your 'walnut' tree.

I'd like to see a picture of a fuzzy yellow walnut. Hay everybody it could exist somewhere in da world !##!
How many of you know what a Horse Chestnut is ? Is it edible ?
😎😎😎

I realize Denise said she was a master gardener.

Walnuts are not produced until the tree is at least 8 years old, by then the roots would be long enough for the juglone to affect plants around it, unless the plants are tolerant, which I do not believe tomato nor the lilac would be tolerant. Black walnut trees are also not rampant self-sowers, as the black locust is, which looks similar. I have lots of experience with black walnut, as we have two very old black walnut trees and also quite a few locust, which self seed often and can appear similar to walnut when young trees.

Edit: My last comment was related to the fact that some people appear to have multiple log ons and No-Tech answered that yes, it was a black walnut.

Philipwonel said:
How many of you know what a Horse Chestnut is ? Is it edible ?

A horse chestnut is not edible, it is poisonous. Popular with kids for playing "conkers" in the UK though.

Yellow fuzzy baseballs would describe a chestnut tree.