elitemittens
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Black Walnut Tree Too Close to Garden?

so, I had a brand new garden set up before I knew that black walnut trees are incredibly toxic :( my garden is maybe 20-25 feet away from this giant black walnut tree. It seemed like a good spot, fairly sunny, not many rocks around(our yard has SO many rocks) and it wont flood here like the rest of the yard. Did I doom myself by putting my garden here? I'd move it if I hadn't already put down manure, leaves and compost. :(

imafan26
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Re: Black Walnut Tree Too Close to Garden?

Is this a raised bed or in ground garden?

If it is a raised bed and you used some kind of barrier under it it may be a few years before the roots from the black walnut invade the bed.
I would look to relocating the bed in the future or if you have a lot of rocks issues build a raised bed farther away. Most tree roots will travel laterally as far out as the unpruned canopy and black walnut can travel twice as far.

Black walnut are infamously toxic to a number of plants but not all of them. There are a few of them that can coexist.
Many plants such as tomato, potato, blackberry, blueberry, azalea, mountain laurel, rhododendron, red pine and apple may be injured or killed within one to two months of growth within the root zone of these trees. The toxic zone from a mature tree occurs on average in a 50 to 60 foot radius from the trunk, but can be up to 80 feet.

You can get around this by planting the sensitive plants in large pots instead or well away from the walnut tree.
https://ohioline.osu.edu/hyg-fact/1000/1148.html
Last edited by imafan26 on Mon Jan 18, 2016 1:32 am, edited 1 time in total.
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elitemittens
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Re: Black Walnut Tree Too Close to Garden?

in ground. Its a bit farther out than the edges of the branches

HoneyBerry
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Re: Black Walnut Tree Too Close to Garden?

Juglone is the name of the toxic chemical.
Vegetables & fruits that are tolerant to juglone:
Onion, Beets, Squash, Melons, Carrot, Parsnips, Beans, Corn
Cherry, Nectarine, Plum, Peach, Quince

My yard is near a walnut tree*, but not as close as what you have. I have not noticed any effects on my plants. The edge of my yard is about 30 feet from edge of walnut tree canopy. The fruit-veggie garden is about 60 feet away. I grew fantastic tomatoes there, which is one of the juglone sensitive plants. My veggie garden is raised and includes lots of mulch. That helps. Obviously, it is best to not use any of the walnut tree leaves or twigs or walnuts as mulch. The squirrels bury walnuts all over my yard and so I often have walnut tree sprouts scattered about. I dig them up before they get very big.
I think you do need to be careful about what you plant and how. I like imagan26's suggestions.
A barrier wall would keep the roots out of your garden, but it would need to be deep enough, and would be a lot of work to build initially. Cutting the roots to build a barrier wall would affect the tree. I don't know if building a barrier wall that close would kill the tree or not. And I don't know how it works if you don't own the tree but the tree affects your property or vise versa, but these are things to consider. In my case, the walnut tree belongs to my neighbor. It sounds like the walnut tree belongs to you in your case.

* I don't know what kind of walnut tree is near my yard. May or may not be black walnut. The tree is old and huge.
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elitemittens
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Re: Black Walnut Tree Too Close to Garden?

I think I may try to plant a few things this year and see how it goes. I guess I'll be amending the soil for my new garden this year :/ how far away does it have to be form a black walnut? our black walnut is between 100-200 maybe? its starting to rot from the inside out. theres no problem with maple trees right?

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rainbowgardener
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Re: Black Walnut Tree Too Close to Garden?

Well, other trees do not secrete the juglone, which is toxic to a number of plants. But all large trees cast shade and suck up a lot of water and nutrients. When we bought our last house, the patio in the back yard was a relatively sunny nice area for growing things. By the time we left 14 yrs later, all the trees around it had grown up so much the patio was in almost complete shade.
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HoneyBerry
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Re: Black Walnut Tree Too Close to Garden?

Maple tree roots can be a problem if you plant beneath or too close to the tree. Maots of roots close to the surface. The roots themselves would affect the plants, rather than toxicity. Maples produce lots of seedlings.
Perhsps you could have 2 garden spots. The one that you already started near the walnut tree could have juglone tolerants plants. And then a second garden for tomatoes and othe juglone sensitive plants. Best to plant in a nice sunny open spot.
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imafan26
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Re: Black Walnut Tree Too Close to Garden?

Tree roots will invade any wet and fertile spot eventually. They will be drawn to it like a magnet. The tree, as already mentioned can make it too shady for sun loving vegetables. Eventually, if you don't have a lot of space, trees will outgrow their space and can become a hazard to things like foundations and underground utilities. If you do have the space they are magnificent to have around. On the other hand trees can have a cooling effect on their surroundings. If you live somewhere hot it can keep a house cooler.

I loved the tree that was in my yard. it was a rubbish tree but it had small leaves. When we bought the house in 1989 it was just about 10 ft tall. Over the years it got to be so big I could no longer prune it myself and we rented the house for a couple of years and the tenants never watered the yard. the tree roots came up and the branches started to split and rot. The roots started heading closer to the house and the water lines so I had to have the tree cut down. The house is not as cool. I don't have the protection from the wind and driving rain, and that side of the house gets beat up by the sun. I also have less privacy since there is a picture window on the second floor.

It was actually a good tree for the yard since it was slow growing, and a male so there were no seedlings popping up all over the place, but eventually it just outgrew the space. It was about 40 years old and 30 ft tall and I had to prune it annually. The leaves would have to bee cleaned out of the rain gutters or they would overflow.
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Gary350
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Re: Black Walnut Tree Too Close to Garden?

If you decide to cut down the walnut tree it is worth a lot of money. It makes a very nice hardwood floor. Have it cut into 1x4 or 1x6 boards any length as short as 1 foot long. Bees wax the board tip ends so they dry out the same speed as the rest of the board so they don't crack then stack in cress cross layers until boards dry in a dry building or garage about 1 year.

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Re: Black Walnut Tree Too Close to Garden?

English Walnuts do not produce juglone; Black Walnuts do and the roots do not stop at the edge of the canopy. They can extend up to double the canopy distance. I have several Black Walnuts in the yard and they tend to stunt plants within their realm. The nuts are full of juglone and even the leaves contain the toxic until they are composted. Do not add walnut leaves to a regular compost pile if you are going to use it on your garden. I have a separate space for black walnut leaves. All part of nature's magnificent pageantry.
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jal_ut
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Re: Black Walnut Tree Too Close to Garden?

"my garden is maybe 20-25 feet away"

I would go for it. Good luck!
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HoneyBerry
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Re: Black Walnut Tree Too Close to Garden?

Now that is a beautiful floor, Gary350.
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ButterflyLady29
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Re: Black Walnut Tree Too Close to Garden?

All trees in the walnut family produce juglone. Some produce more than others. Black walnut and butternuts are the worst.

Any tree near a garden is asking for trouble down the road. Trees are constantly growing and can send roots many many feet beyond their canopy. I've been digging mulberry roots out of one of my gardens and the tree is 60 feet away from the garden, the canopy is 40 feet away. Tree roots will take the nutrients and water from your garden soil. There are few plants that can cope with tree root competition but those are worth the effort.

This site gives a good listing of plants that are and aren't tolerant of juglone.
https://knechts.net/wp-content/uploads/2 ... e-List.pdf
You can still grow quite a number of crops in your garden. And some that aren't tolerant can still be grown in pots. I've got a terraced shade garden in the works which consists of a bunch of big pots under a huge sycamore tree. At the outermost edge I have a line of black raspberries which do just fine in partial shade and tolerate the tree root competition.

elitemittens
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Re: Black Walnut Tree Too Close to Garden?

the garden is actually about 40ft away from the base of the tree! Sorry for the miscalculation... I'm not very good at estimating distance. And I have a whole new garden spot picked for next year! no trees in sight of it ;)

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jal_ut
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Re: Black Walnut Tree Too Close to Garden?

Quote: "the garden is actually about 40ft away from the base of the tree! Sorry for the miscalculation... I'm not very good at estimating distance."

You should be OK. I would certainly plant and see how it goes.
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/-

burlington05
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Re: Black Walnut Tree Too Close to Garden?

We just took down 8 beds that were within 20 - 30 feet of the neighbors trees. He actually just let the squirrels plant them and now he has a good acre of them. Make plans to move your beds although I would certainly give it a try this year. From what I understand the Juglone is in the roots and some in the bark. The nuts also have it and when they fall to the ground that leeches into the ground and creates more problems. In our neck of the woods, Black Walnuts are common. We have a good 1/2 acre of them as well, fortunately they are at the back of the property. We built two new beds for me in the front of the house on the driveway. Much easier for me and now no worries about Juglone, snakes and the occasional snapping turtles.
Good luck.

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