Is walnut tree sap usable? Can you drink it, for instance?
We have not heard of drinking the sap of the black walnut tree, nor has the staff at the University of Vermont’s Proctor Maple Research Center in Underhill Center. There are, of course, many uses for other parts of the walnut tree: food from the nuts; wood for furniture and gun stocks; oil from the seeds, used to make solutions for cleaning and polishing metal surfaces; and a dye for wool and artists’ colors from the shells. We caution you not to grow other plants near a walnut tree. It has been observed that tomato plants growing too close to a walnut tree will wilt, because the walnut’s roots exude a toxic substance. The walnut has this ability so that it can keep other plants away from its root system and provide the right environment for its own seedlings to grow. We wouldn’t recommend imbibing walnut sap.