AboutJim Hyland Expertise I am an expert in Forestry, Forest Entomology, Forest Pest Control, and Forest Health. Extensive knowledge in Identification of insects and diseases of trees. Expert on Bark beetles and other insects that attack forests. Also a Registrated Forester with extensive knowledge in the management and care of forests.
Experience 34 years as State Pest Management Chief in a Southern state. Extensive knowledge in Forestry.
BS with major in Forest Management and Entomology Registered Forester Certified Pesticide Appicator
Expert: Jim Hyland Date: 7/3/2008 Subject: Sap from a Black Walnut Tree
Question Goodmorning,
Do you know if Sap from a Black Walnut Tree will DAMAGE Treated Wood? I want to build an Arbor under a Black Walnut Tree in my backyard but my husband says the Sap will damage the wood... Do you know if this is TRUE?
Thank You So Much For Your Help, Michele
Answer No the sap from a walnut tree will not damage wood. Walnuts do contain a chemical that will kill other plants near the tree. When certain other landscape plants are planted near or under this shade tree they tend to yellow, wilt, and die. This decline occurs because the walnut tree produces a non-toxic, colorless, chemical called hydrojuglone. Hydrojuglone is found in leaves, stems, fruit hulls, inner bark and roots. When exposed to air or soil compounds, hydrojuglone is oxidized into the allelochemical juglone, which is highly toxic.
These toxins will not damage the wood since it is not living cells.
