Utilizing Black Walnut Shells

Hey everyone, I've started processing a few hundred pounds of black walnuts. But I'm left with a lot of shell fragments, any ideas what I could use these for? Mulch? Biochar?

Welcome to the forums Devin!

Black Walnut hulls* contain a compound called Juglone that can discourage plants from growing via allelopathic characteristics.

Recently, I discovered that if you soak the hulls* you can use the resulting water slurry to extract and kill asian jumping worms out of the ground (Allegedly, I need to test it).

I hear you can also powder the hulls to make natural stain/ink.

*EDIT - Hulls not shells! Oops!

We buy crushed walnut shells for our sandblaster cabinet. We also use them in vibratory cleaning machines. Reloaders will come buy a coffee can full to clean their brass for reloading.

Do you mean the hulls or the shells? Hulls are the outer thick layers that turn from green to black and contain juglone. Shells are the middle hard layer which you crack to get to the nut meat.

I use the hulls as mulch directly for fall crops that are not sensitive to juglone such as garlic. Or I pile them up to decompose over the winter and the toxicity will be gone. For the shell pieces from cracking walnuts I usually put a thick layer on top of the soil of my potted plants. They are slow to break down and make great mulch similar to cocoa shells but free.

There are people selling both crushed hulls and shells online. Maybe you can look it up and see how they are being used.

May Lotito wrote:Do you mean the hulls or the shells?

Honestly, I didn't appreciate the difference! Thank you for bringing that to my attention, a search confirms Hulls contain the most.