Should one have a concern about planting a seedless Kentucky Coffee Tree (Gymnocladus dioicus)? I have read online that the leaves and bark can be poisonous.
Answer
I am attaching Michael Dirr's description of the Kentucky Coffee Tree Gymnocladus dioicus from his encyclopedic work, The tree book : superior selections for landscapes, streetscapes, and gardens.
Dirr loves this tree. "To sit underneath [the Kentucky Coffee Tree] is a religious experience to a tree lover." He recommends that home owners choose seedless cultivars because the large seed pods can get messy. This tree (males only) is also on Philadelphia's approved street tree list.
According to Missouri Botanic Garden's PlantFinder,
"Native Americans and early American settlers, especially those in the Kentucky territory, roasted and ground the seeds to brew a coffee-like beverage (albeit no caffeine), hence the common name. Native Americans roasted the seeds for food. Seeds are very toxic prior to roasting, and should never be eaten fresh off the tree. Trees are late to leaf out in spring and are one of the first to drop leaves in the fall."
Neither of these extremely reliable sources mention any problems with the leaves and bark being poisonous to humans.
Hope this helps, and thanks for contacting PHS.