Hi Vince, 

You can dry walnuts either in the shell or after shelling them. Shelling takes considerable time, of course, but it does speed up the drying process.

Either way, the first step in drying the walnuts would be to remove the husk. When the rains start up in western Oregon, the husks will usually start to crack open naturally and make it easier for you to remove them and expose the shell, so this is the best time to harvest. After you have peeled off the green husk, you should spread the walnuts out on screens or hang them in a mesh bag (such as an onion bag). The goal is to allow air circulation around the shells. Ideal temperature is between 95 and 105 degrees. You can place them in front of a radiator or a forced air heater, but the lower the temperature the longer it will take to dry them. 

You'll know the walnuts are ready for storage when you the halves of the shell break open with a clear "snap." For the longest storage time, you can refrigerate or freeze the nuts in jars or freezer bags. Frozen, properly dried walnuts will stay good for as long as two years. 

You can read more in our publication about storing nuts from a home orchard.

Thanks for using Ask Extension!

Jared