Above Left: When a ripe Black Walnut or Butternut Hull(or Husk) begins to deteriorate, it has dyes that will stain your fingers an indelible brown.
Cooked Hulls make a very effective Easter Egg and Hair Dye, Woodworking Stain, and Fox Trap scent remover. It is also used in Natural Remedies.

Use a cooking tongs to put them in a Bucket. Then place a two-foot square piece of 1" mesh Hardware Cloth on the ground under the Walnut Tree to aid in hulling.
Slide your boot forcefully over the Hull to roll it on the mesh,
and remove the Walnut from its Hull.

The Hull should be at its spongy stage to do this. Usually those which have dropped naturally are ready for hulling. They are not picked like apples or Oranges.  If you pick them from the tree, they may be too green and refuse to release the Walnut. Most bearing trees have their limbs too high to allow picking. 
Lower limbs often drop off as a tree matures.

Above Right: This small hand-cranked Antique is a great Walnut Huller. 
Bolted to a plank, and anchored securely, this makes a worthy Walnut Hull Removal Tool. A 5-gallon bucket placed beneath it will catch most of the hulled Walnuts. Note the aggressive teeth on the wheel, and the spring-loaded adjustment (Red arrow) which applies pressure to the toothed wheel.

The insert shows four green Walnut Hulls which are not ready to be removed.
The three above them are just right for hulling.
The top two may no longer be useful.

Larvae of the Husk Fly eat the Hull of the Black Walnut,
but do not damage the nut inside.

If you have a really lot of Black Walnuts to hull,
we have Plans to convert a Cement Mixer to a Walnut Huller.

My Father noticed that Walnuts which fell in his driveway were separated  from the Hull by his car tires, and so he would move the others into his driveway to eliminate the Hull removal chore. The tires seldom damaged the very hard shells.

A wire Potato Basket makes a good tool to remove the Hull residue when it's agitated vigorously in a bucket of water. Then allow them to dry in the sun at a location which is not accessible to Squirrels or Neighbors.   

Cracking a Black Walnut requires a bit of effort. An English Walnut Cracker will not come close.  A hammer and a Brick will work; so will a strong Vise, which you can close on each Walnut. This is slower, but has the benefit of very few damaged Nut Meats. A Cracker made especially for Black Walnuts makes the job easier.

The trick is to stand the walnut on its pointed end. When hit on the top point,
it will fracture on its midline, resulting in larger Nut pieces, 
which are easier to remove from the Shell.

Antique Cracker shown Above Lower Left is a mechanical marvel. 
When the Handle is lifted, the Ram opens to allow insertion of a Nut. 
Then when the Handle is lowered, the tapered Wedge slides 
to automatically adjust to the size Nut you are cracking. 
It goes from Black Walnuts to much smaller Filberts without missing a beat. 

Then additional lowering of the Handle rotates a Cam which exerts great force on the Ram and the Nut Shell. Many Nuts have been cracked with a Hammer by standing them on their point to cause them to fracture around the center. But this procedure may be determined by the shape of the particular Nut. Some are "tall" and some are "fat" which may cause them to fracture differently.

The Hulls contain a Toxin called Juglone. It is also contained in the roots, bark, and leaves of the Black Walnut tree. It is thought to be harmful to Horses. 
It is KNOWN to be harmful to garden plants, especially Tomatoes 
which become wilted as though blighted. 

It is prudent to distance other plants from your Black Walnut trees. Some think the Toxin will dissipate during composting. But it may be wise to limit the amount of Black Walnut sawdust, leaves, chips, and Hulls in your Compost.

A strange  plus for Fishermen: when you empty Walnut wash into mowed grass, Fishworms race for the surface! They may be sensitive to the toxin Juglone, in the Hulls. Some Fishermen say that a burlap bag of mashed Walnut Hulls swished in a stream will cause the Fish to float to the surface.

Planting of Trees should be done when they are less than two feet tall to minimize root damage. If you plan to harvest the Nuts, plant them in your youth; they grow slow and big (Which makes them a great inheritance for your children).

There are very few investments that guarantee the return of a Black Walnut Tree, when you consider the very minimal investment. Call your local Building Center and ask the price of a Black Walnut board 8 inches wide by 8 feet long.

Black Walnut Trees have very few enemies and require minimal maintenance.  A yearly Spring pruning of 1" lower limbs is about it! If you plant them twelve feet apart in rows that are twelve feet apart, they will grow straight and tall and yield very expensive lumber in years to come. A 70' tree is not unusual.

They don't make the best lawn trees. They invite Squirrels to dig up the area to plant the Nuts. And they are about the last tree to leaf out and the first to drop their leaves with their associated twigs, which along with the nuts, constitute a considerable clean-up job every early Autumn.

Thomas is a cultivated variety which is said to produce larger Nuts with thinner shells . . .  What will they think of next ?

Juglans cinerea

These are Butternuts which tend to grow where Black Walnuts grow.
The Hull has characteristics similar to Black Walnuts, but it is sticky.
They are long rather than round, and have a unique buttery flavor.
The native trees tend to be victims of diseases and Canker.
The roots tend to protrude above the soil.