Not all plants are sensitive to juglone, such asdogwood,juniper,clematis, anddaffodils.
Its large, mature size and canopy make it a desirable shade tree.
As a native tree, black walnuts provide food and shelter for wildlife.
The Spruce / Evgeniya Vlasova
The primary beneficiaries of the nuts are squirrels.
The eastern fox squirrel gets 10% of its food from black walnuts.
Even after a black walnut tree has been cut down, the remaining roots will continue to release juglone.
The Spruce / Evgeniya Vlasova
This will allow you to grow sensitive plants such as tomatoes in raised beds.
The affected plants cannot be treated and usually die within a few months.
Thats why its important to know how to identify a black walnut tree.
The Spruce / Evgeniya Vlasova
Tip
Nurseries often sell English walnut scionsgraftedonto black walnut rootstock.
Grafted trees have better resistance to pests and diseases than English (Persian) walnut trees.
However, both grafted and non-grafted black walnut trees will affect juglone-sensitive plants.
The Spruce / Evgeniya Vlasova
The trunk appears especially long because the first branches start at a high level.
The bark of young trees is grayish and scaly and over time darkens and develops intersecting diamond-shaped ridges.
The dense crown is rounded.
The Spruce / Evgeniya Vlasova
Black walnut leaves are large, up to 24 inches long.
What is acting like individual leaves are single leaflets.
The fall color is yellow to brown.
Tree of Heaven leavesWhiteway / Getty Images
The yellow-green husk turns black after dropping.
Neither tree will grow as tall as a mature black walnut.
Collect them daily to beat the squirrels to them.
Staghorn Sumac flower clusterMichael-Tatman / Getty Images
Wear work, gardening, or disposable gloves when handling black walnuts because the tannins leave pesky stains.
Remove the green husks promptly after harvesting before they turn black and mushy.
Use a shovel to loosen the surrounding soil and remove the entire taproot.
Black walnuts in various degrees of maturation, from green husk to nutP.A. Collins / Getty Images
Cut down a larger treeand remove the stump immediately by grinding it orusing another methodor it will resprout.
To prevent sprouting, coat the freshly cut stump with a stump killer available at your local garden center.
Most stump killer products contain potassium nitrate as the active ingredient.
It contains a high amount of nitrogen, which speeds up the decomposition of the stump.
Another option is to treat the stump with glyphosate, anon-selective herbicide.
Alternatively, hire a certified arborist to grind the stump out mechanically or remove it.
Girdling the tree is not a great option.
Black walnut trees live on average 150 years but can live much longer in ideal conditions.
Several factors can go into deciding whether or not to cut down a yard tree.
Landscaping and Gardening Around Walnuts and Other Juglone Producing Plants.The Pennsylvania State University College of Agricultural Sciences.
Luna Moth.Missouri Department of Agriculture.
Black Walnut Toxicity.The Morton Arboretum.
Black Walnut Toxicity.University of Wisconsin Division of Extension.
Black Walnut.Ontario Ministry of Natural Resources and Forestry.
The Cold Hard Truth: Selling Walnut Yard Trees.University of Illinois Extension.
