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| In mid-November, 2025 I hired a gentleman to run a trenching tool between the walnut trees that were east and down-slope of the Hill Orchard. |
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| Most of the roots he cut were not very big, between the thickness of 14-2 Romex and garden hose. I expected them to be thicker. The trench was 35 feet from the closest tree trunks. |
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| A few of them were a bit thicker than that. |
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| This picture was taken today. The walnut trees (and a swamp) are to the left of the image. The trench is the slightly lighter green strip diagonally through the center of the frame (top-to-bottom), Upslope of the trench, where you would expect it to be drier, is GREEN. |
The walnut roots are still leaching toxins into the soil but they are not sucking moisture and nutrients out of the topsoil.
Frankly, I am surprised by how brown and stressed the grass on the left side of the image is compared to the left right side. Bottom-line, tree roots are devastatingly effective at extracting moisture and nutrients from the soil.
You can see this in farm country. Corn growing within 2X of the tree's height will be stunted and runty during dry summers.
Note for TB: It isn't just the shade. You might consider raised beds with a barrier beneath them to prevent the tree roots from infiltrating the beds. Or, if they community garden managers allow it, trench around your plot...as an experiments...to see if it makes a difference.
How deep was the trench?
ReplyDelete30 inches, give or take a little bit.
DeleteI was afraid it would not be deep enough to make a difference.
Most of the roots were in the 6" to 8" deep range.
Tree roots also 'love' sewer pipes... sigh
ReplyDeleteMy garden ground is surrounded by spruce and willow trees. I have hit spruce roots thirty feet from the nearest tree. Also had a raised bed invaded by a. Willow tree ten feet away. This is in Alaska and the trees were chasing irrigation water. I did slow the process by borrowing a 3 point hitch chisel plow an ran around the bigger piece with it as deep as it would go.
ReplyDeleteFire weed and mares tail risomes are almost worse. They will run under the boards of my hoop houses to the beds and require annual deep work up of the. Outer beds to stop them. I suppose a deep barrier would solve it but I’m to old and feeble to do that didding!
Thanks ERJ. Some folks have some element of raised beds in the standing lots so that is possibly a longer term possibility.
ReplyDeleteThat picture is very telling.
That photo is an excellent illustration of how much of what has been incorrectly attributed to 'juglone toxicity' is actually a result of the larger black walnut tree, with extensive root system (and shading) outcompetes smaller, less deeply-rooted plants growing in its root zone.
ReplyDeleteAs an 8 yr-old, I rooted some cuttings from a pomegranate tree growing at the home of a friend in the little rural community where I grew up, and planted them at my grandparents' home... 20 & 30 ft from the trunk of a (then) young BW seedling. They grew, but never fruited... for 35 years, until my parents (now living in the family home) had to install new septic field lines, and a trench was dug from the septic tank to the new leach field, passing between the BW and the poms. They EXPLODED into fruiting!
I is easily confuse:
ReplyDelete"left side of the image is compared to the left {right?}side"
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Mom complained her tomato plants never did much. I noticed they were near the walnut tree. I put a store-bought tomato plantling in the ground 200 feet away. It's HUGE. Huh.
Gum-daggit. You figgured out that I am Lyzdexic.
DeleteFixed it. Thanks.
-Joe
I remember when you cut that trench, thank you for the followup.
ReplyDeleteBut how are the trees doing, did they suffer any distress, lose the nuts early?
It is hard to tell with walnut trees in the wild. The mast crop is highly variable from year-to-year.
DeleteI still had newly planted pear-trees to Tango-Uniform near the bottom of the Hill Orchard. Good thing that I can make them dirt-cheap.
The internet, which is sometimes right, suggests that it takes about five years for most of the walnut toxicity issues to biodegrade.