Friday, September 29, 2017

Black Walnut trees: The "death zone"

            Where I was landscaping today had a number of Black Walnut trees. I learned from the homeowner that the Spruce trees they planted a couple years back died; they were told it was because of the Black Walnut trees. That got me thinking about what other plants might not do well under these messy things.

            But first let me tell you why some things don’t grow well under them.

            The Black walnut produces a chemical called Juglone, and it is a nasty secretion that seems to kill plants from within. The “killing zone’ is within the root system of the tree; which typically is as wide as the tree canopy. You might want to go out an additional 10 to 15 feet just to be on the safe side when planting.

            Plants that cannot live under this tree are:

            Tomatoes, peppers, potatoes, rhubarb, asparagus, red peppers, eggplants, basil, most Rhododendrons, petunias, azalea, viburnum, blueberries, and Spruce trees.

            Black Walnuts are not the only trees that produces Juglone. This chemical is also secreted in smaller amounts by English walnut, and hickory. Others trees that could give your plants fits are: sugar maple, hackberry, American sycamore, American elm, cottonwood, black cherry, sassafras, red oak and black locust. If you seem to be having a “growing” problem near or under these trees this may be why. They don’t secrete Juglone, but it is similar.

            There is no cure; it’s just the nature of this beast. The only solution is to not plants the plants mentioned. Sorry.

 If you have any questions feel free to e-mail me at or post a comment on this Blog. Like us on Facebook at Niemeyer Landscaping.

1 comment:

  1. i am interested in farming and gardening so much that i read informative blogs like these in my free time, all the time. this post is quite useful to me in many ways. thank you for posting