Walnuts can be harvested as soon as hulls can be removed easily. The nuts can be picked from the tree, shaken out or knocked from the tree with a light pole, such as bamboo. Care should be taken not to injure the bark of the tree. Many home owners will prefer to let the nuts drop naturally. Filberts should be left to fall from the tree naturally, or brought down with a very light shaking of the tree limbs.
Both walnuts and filberts should be picked up frequently (at least twice a week) and the drying process started. They can be sun dried if protected from rain and dew, placed in small mesh bags and hung in a warm room or attic, placed in shallow trays in an airy room or loft, or oven dried (stir every few hours while drying). Some artificial heat, in a heated room or an attic above heated rooms, is desirable in Western Washington.
If direct heat is applied, as in an oven, the temperature should be held at 90 to 100 F. It should never be allowed to go above 100 F. Too rapid drying will cause shriveling. Thirty-six hours should do the job if temperatures are close to 100 F. A week or more may be required when no artificial heat is used.
Walnuts are dried sufficiently when the thin membrane between the two halves becomes brittle so that it will break readily.
Filberts are dried enough when the meats lose their rubberiness and become crunchy when chewed. Overdrying by artificial heat can cause unnecessary shrinkage of the nut meats.
After drying they can be stored in net bags hung in a warm dry place for at least a month. Then place in large glass jars with tightened lids and store in a cool, dark and dry place.