But before they do, you might want to eat some. Why? If you break a walnut along its handy dandy seam, you can open it up and reveal something that looks like your tiny shriveled brain inside your skull. Now, how cool is that? All the benefits of being a zombie without having to get your clothes dirty.
But where do walnuts come from? You can wait forever until a wall hatches some out. But walnuts do fall from the sky, like magic. And that's because your good friends, the crows and the squirrels, like to eat walnuts, too. Just not whole like you. They will go somewhere high up and drop walnuts against a hard surface to crack them open. That would be any hard surface like a parking lot, a car or your head when huge diamonds aren't available. So, just stand out anywhere where those critters are hard at work and grab dropped walnuts before they can get to them.
You are going to find that some of those walnuts are still going to have some husks on them. Those things will stain your hands like nobody's business. This is why crows and grey squirrels are the colors they are. So wear gloves and tear off the husks and give your nuts a good wash. Then dry.
Now most people prefer just to eat walnuts whole, but if you are a sissy, you can crack them open and just eat the meat inside. So, you will need a nutcracker. You may recall the boring opera by Tchaikovsky and the soldier design used for that nutcracker. This is based on what kings and queens used to do. They would place a walnut in a guard soldier's mouth, then drop an anvil on his head to crack a nut. You can get your kids to dress up and use them to crack walnuts the same way. Be aware that this works only for English Walnuts. American Black Walnuts have much harder shells and will require a pile driver, with used ones available on eBay.