This is a subject that I have followed with interest, more than just a few years ago a friend and I spent our winters scouting and cutting walnut trees here in Central California. Trying to determine the different species of walnut growing in this area is difficult, most of the thin shell walnuts are grafted on a thick shell root stock, it might be Black, Claro or Bastogne. Most of the nursery trees that are planted now are on Bastogne rootstock because of its disease resistance and success as far as grafts are concerned. Bastogne is supposedly a hybrid between Juglans Nigra and Juglans Regina. Quality of the wood can vary from tree to tree, depending on where and how it has grown and to say that Claro is soft and brittle is not always true, I have seen Claro that was dense and quality wood and thin shell that was soft and useless. When cutting a tree you never knew what you had as far as color and quality until you cut it open. I have seen Bastogne in many different colors and quality; the dark brown colors seem to be very dense and have excellent figure. My experience is that each blank should be individually judged, keep in mind that most walnut in California is from orchards, with a few trees that were yard or wild trees.
Jim A.
