Black walnuts are ready to be harvested when the hull can be dented with your thumb. You can also wait until the nuts start falling from the tree. Either way it is important to hull walnuts soon after harvest. If not removed, the hull will leach a stain through the nut and into the meat. The stain will not only discolor the meats but also give them an off flavor.
There are several ways to hull walnuts including running them through a corn sheller or pounding each nut through a hole in a board. The hole must be big enough for the nut but smaller than the hull. An easier way is to run over the nuts with a lawn tractor. This will break the hull but not crack the nut.
Note that walnut hulls contain a dye that will stain concrete, your hands or about anything else it touches. Wear gloves as the stain is almost impossible to remove.
Wash hulled nuts by spreading them out on the lawn or on a wire mesh and spraying them with water or placing them in a tub of water. If you place them in a tub, the good nuts should sink.
Those that float are probably not well-filled with kernels. Next, dry the nuts by spreading them in layers no more than three deep in a cool, shady and dry place such as a garage or tool shed. Drying normally takes two weeks.
Amending Soils with Sand
Sand is sometimes suggested as an amendment material for clay soils.
However, there is good reason to be cautious about using sand. In order for sand to be effective in breaking up a clay soil, sand grains must touch one another so there are pore spaces between grains that can hold air and/or water. If the grains do not touch, the clay fills in all the voids between the sand particles leaving no room for pores.
This is the same principle used to make concrete and the result is somewhat the same. You end up making a bad situation worse. So how much sand does it take for it to be effective?
Normally, we consider about 80 percent sand to be sufficient. In most cases this makes the use of sand impractical. The addition of organic matter is a much better choice.