Every few days between Halloween and Thanksgiving, I scoop up any brown shells from the ground under the walnut trees and toss any fallen nuts still encased in hulls against the red barn to let the outer coating weather itself off. That way, I avoid staining my hands black from the phenol chemicals in the hulls. Some people use walnut hulls for making black or brown dye.
I wonder if the chemical in the walnut hulls also reduces the number of predators willing to chew through to the nut. Squirrels seem to be immune. Although English walnuts are not native to the North American continent (they originate from southwest Asia and are sometimes more correctly called Persian walnuts), our local wildlife collect them from yards and orchards. Squirrels are famous for stripping my friends' urban walnut trees. I am fortunate that the farmyard is surrounded by a broad band of grassland which the native western grey squirrels are not willing to cross from the hillside forests. There are, however, rodents that apparently collect walnuts at night because throughout the winter I find emptied shells in the barn with small holes chewed through the end.
Most nuts for human consumption need to dry for days to weeks before they are eaten. Last winter, I dried my walnut crop in the garage in open cardboard boxes covered with metal wire refrigerator shelves. Eventually, however, rodents raided the stash and the garage floor was strewn with broken shells. At first I couldn't figure out how the mice got the fat shells out of the boxes which were still sturdily covered with the wire shelves. Then I decided extra skinny mice had been assigned the mission to slip through the wires, crack the nuts inside the box and toss the pieces through the bars to their hungry families waiting outside.
This year, I am pouring the collected walnuts onto an old screen door suspended between picnic tables under the maple trees. I clamp a set of window screens on top to discourage raiders. So far it is working, although at first, I expected to hear crashing noises from the clever raccoons unscrewing the clamps some night. The raccoons (who ate my entire pear and persimmon crops this year) haven't shown up, so maybe their smirky mouths and sneaky hands aren't strong enough to crack open walnut shells. I hear the great-horned owl every night now, and sometimes a pair of screech owls, so they must be keeping the skinny mice away.
Every few days, I turn the walnuts to ensure thorough drying. It's a meditative process rolling the walnuts and lining them all on their long sides so the top screen will clamp down firmly. The other day while I was rolling walnuts, the local flock of acorn woodpeckers landed in the maple trees above me, chattering about their day of acorn harvesting. It reminded me about their special techniques for storing and drying acorns in a pecker-made granary.
Acorn woodpeckers work in extended family groups to harvest acorns and store them in their own granaries - tree trunks, power poles and fence posts that they have riddled with long rows of holes. They check the granary every day and since the acorns slightly shrink as they dry, the woodpeckers will move any loose acorns into tighter holes to prevent other animals from robbing their stash. I haven't found the acorn woodpeckers' cache on the Dipper Ranch, however, every morning they visit the maple trees by the house and conduct a short shouting match with the earlier arriving Stellar jays, so the yard must be somewhere between their nighttime roosts and granary trees. (Painting of acorn woodpecker above by Bob Hines, United States Fish and Wildlife Service)
Ninety-nine percent of the US supply and two-thirds of the world supply of English walnuts are produced from extensive orchards in the Central Valley of California (www.walnuts.org). Commercial harvest of walnuts is largely mechanized. First the orchard floor is rolled or dragged clean, then the walnuts are knocked loose from the trees by large shaking machines, and finally the fallen walnuts are blown into a row and swept up my mechanical harvesters.
I'm glad I get the chance to pick up the walnuts by hand. They make a lovely sound when they plunk into the bucket and many of my friends and family while talking to me on the cell phone in the fall, exclaim, "I hear walnuts. Will you save me some?"
For a hilarious description of the hippy lifestyle of California's acorn woodpeckers, see the Bird Watcher's General Store.