English walnut trees---Juglans regia---are grown commercially, producing nuts in five or six years, though they're not mature until after a decade. When growing wild, walnut trees can grow to 100 feet, though, when cultivated, they grow 20 to 50 feet. The round nuts not only have a shell, but also a green and fleshy husk or shuck. The actual shell of the walnut is thin. The walnut harvest should coincide with the shuck coming off or cracking naturally with rains, which happens in autumn. The cracked husks let the nuts fall to the ground. That's when the nuts are ready.
Shake the walnut tree gently, making sure to not to damage the bark, which will damage the tree. Nuts that are ready to fall, will fall. Don't use force.
Grab limbs with the hook of the plastic pole and reach into the tree to give the limbs a gentle shake.
Gather the nuts with cracked shucks only, both those that have fallen to the ground naturally from the elements and those that have fallen as a result of the shaking. Wear gloves because chemicals in the husk can irritate your skin.
Leave nuts that don't have cracked husks on the ground until the hulls are loose or crack, which will take one or two weeks.
Shuck the nuts, then shell them.
Place the nuts on the rack or screen and set the rack in the tray. Don't crowd the nuts---they need air circulation.
Place the rack in a warm place---say, above a radiator---with temperatures of about 100 degrees Fahrenheit.
Store walnuts when they are dry, which will be when the dividing material between the halves of the nuts snap easily, about three or four days.