Black walnuts are a stately tree prized for their valuable lumber and plentiful walnut production, but they can also pose a problem when landscaping or for households with children and pets. Thanks to a unique survival adaptation, these trees leach a toxic substance known as juglone into the soil, and it can also accumulate in the leaves, bark and hulls of their fruit. Typically, you can work around the toxic tendencies of black walnut trees through some careful landscaping. But if you have a small yard, curious children or animals prone to browsing on nearby plants, it may be best to remove the tree entirely.
Understanding Juglone Toxicity
Juglone is a natural chemical compound that inhibits metabolic growth in plant cells, and it has been shown to possibly cause cellular deterioration and death in human cells as well. Black walnuts release juglone through their roots to discourage plant competition in their immediate area, increasing their own odds of survival, and walnut leaves have traditionally been used as an herbicide because of this chemical. Although juglone is typically not an immediate health concern for humans, it can cause vomiting and neurological problems in dogs and other animals such as horses.
Landscaping With Juglone-Resistant Plants
If you have a relatively small space to work with while landscaping, a black walnut tree can pose a significant problem for any plants you try to grow. Because walnut tree roots can spread both wide and deep, the older the tree, the greater the radius of toxicity surrounding it. You can, however, ameliorate the problem somewhat by choosing plants that are naturally resistant to juglone, such as hostas or vegetables like beans, beets and carrots. Vegetables in the nightshade family like tomatoes, peppers and potatoes are all particularly susceptible to juglone and should be avoided.
Removing The Black Walnut Tree And Roots
If your black walnut tree is interfering too much with your landscaping or resident animals, you may be forced to remove it to salvage the rest of your yard. Removing a black walnut tree is a fairly straightforward process, but in order to eliminate the juglone entirely, your tree removal service will need to remove as much of the roots as possible, since they can still produce juglone for some time after death. With a comprehensive removal and enough time for pre-existing juglone to be flushed from your soil, you should find that your yard is much more hospitable to your gardening and landscaping efforts, and you can rest easy knowing that you no longer have a toxic compound lurking beneath your feet every time you go outside.
For more information or advice on how to handle a problem with a black walnut tree, talk to a tree removal service in your area.