Black Walnut Trees

Facts and Features of the Black Walnut Tree

By George and Becky Lohmiller
October 3, 2019
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Photo by Ascending the Giants: Wikimedia Commons

The black walnut tree (Juglans nigra) is one of North America’s most valuable and beautiful native trees, but it does have a “dark side.”  Here’s what you should know before planting a black walnut in your yard—and all about harvesting and eating walnuts, too.

A Few Black Walnut Tree Facts

  • The easily worked, close-grained wood of the black walnut has long been prized by furniture- and cabinetmakers for its attractive color and exceptional durability. Its logs are in such demand for veneer that “walnut rustlers” have made off with trees in the dead of night and even used helicopters in their operations. 

  • The early settlers discovered black walnuts growing in mixed forests from Canada to northern Florida and west to the Great Plains. They found that its rich-brown heartwood was exceptionally resistant to decay and put it to use as fence posts, poles, shingles, and sills.

  • When surrounded by other trees in the forest, black walnuts grow straight and tall with few, if any, lower branches.

  • When planted in the open, the tree will branch out closer to the ground, developing a spreading shape that makes it easier to harvest its sweet, round, two- to three-inch nuts.

  • Settlers snacked on the nutritious walnuts out of hand, added them to soups and stews, and ground them into meal for baking; the hard shells provided a perfect package for storing the nuts over winter.

Black walnut tree

The “Dark Side” of Black Walnuts

Although the black walnut has many uses and benefits, the tree does come with a caveat: The black walnut’s roots, which may extend 50 feet or more from the trunk, exude a natural herbicide known as juglone in its roots, leaves and fruit husks.

This chemical inhibits many plants’ growth under and around the tree, thereby limiting the tree’s competition, leaving more water and nutrients for itself. 

Tomatoes, potatoes, apples, pears, berries, and some landscape plants such as rhododendrons, azaleas, and lilacs may be killed or stunted if grown in close proximity to black walnut roots.

A Great Shade Tree

In spite of this, black walnuts make great shade trees for larger properties. They commonly grow to 50 feet or taller and about as wide, and specimens of more than 100 feet have been recorded.

Black walnut’s large, fernlike foliage provides light, airy shade for those grasses and ground covers not affected by juglone. In autumn, the leaves turn bright yellow, contrasting nicely with the tree’s rugged, dark bark.

Black walnuts require a deep, fertile soil with a near-neutral or slightly acidic pH. They are pretty much disease-free and are threatened by few pests, with the exception of perhaps an occasional helicopter.

Picking Up the Nuts

Thud! Thud! Most walnut tree owners have a love/hate relationship because of the fruit which the tree drops in late summer though October. The size of a baseball and colored lime green, the fruit is quite heavy. It makes quite a mess and can be viewed as a nuisance.

Walnut tree owners will spend hours picking up the fruit some years. If you don’t remove the nuts, you’ll trip over them in the dark for the rest of the year (while they rot and mold on your lawn). Hire the kid down the street to pick up those nuts *but be careful not to overpay per nut or you’ll go broke)! 

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Photo Credit: John A. Anderson

Harvesting and Eating Black Walnuts

If you’re willing to do the work of cracking the outer shell, the “meat” inside is edible, as the squirrels will attest; squirrels have little problem chewing through the shells. (Note: Black Walnuts are different than English Walnuts more commonly sold in stores.) 

The sweet, earthy nutmeat inside is well worth the effort. Your grandparents may have harvested the walnuts which can be eaten raw or added to baking (cookies and bars). They can also be toppings on ice cream and cakes, enjoyed as a sweetened candy nut, or ground into meal for a unique flour. 

To harvest, collect the nuts as soon as possible to avoid mold and remove the husks immediately. Wear gloves as the husks stain your hands (and anything they touch). If the nut is too hard, wait a few days and it will brown and soften up.) To remove the husk, you can simply step on them gently with an old pair of shoes. Hose down the nuts in a large bucket to remove any remaining husk.

Dry the walnuts for a couple of weeks on a screen or drying rack or in a hanging mesh bag. You can store them unshelled up to a year. Crack the shell with a hammer to get to the nut meat. (Strike at a 90-degree angle to the seam until the nut cracks). Use pliers to easily clip away the shell to release the nutmeat. Allow the freshly removed nutmeat to dry for a day before storing.

Do you have a black walnut tree? Please share your comments, questions, and advice!

Source: 

This article was originally published in March, 2008 and has been updated.

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Reader Comments

Leave a Comment

Barbara - Lumber - cut down tree

I would be interested in removing the tree for you.

walnuts Black

Are the black walnuts still good to harvest underneath the snow

Walnuts

We recently found black walnut trees on our land after clearing brush. It’s the season for them to drop. How can we tell that what is on the ground is this year or a prior year?

lumber

We have a huge, very healthy black walnut tree that we need to cut down. Does anyone buy the logs or any part of the tree?

Walnuts by the Driveway

After reading these comments, I can understand why someone long ago planted two black walnut trees along the driveway! We just moved into our house a few months ago and have been popping over these walnuts for weeks as they've dropped to the ground. I wish I had paid more attention and known they were walnuts before now, as their ripeness has long passed. Everything adds up - squirrels have shown up and have been eating and storing them in our shed, the fruit and the trees themselves have a distinct smell, when I tried to hull one my hands got stained, and the trees are the tallest and strongest trees we have. What a nice surprise that came with our new home. Now to treasure them and get prepared for next year's harvest!

HI! I use thick rubber

HI! I use thick rubber disposable gloves. wait for the nuts to turn brown, and the outside layer squishes off easily. Because they are usually full of worms under that layer, I then toss them back on the ground and let them dry in the sun. I just recently busted open a bag I harvested 2 summers ago. I wish I had harvest and eaten them along time ago! Black walnuts are so much better tasting then english walnuts you purchase in the stores. Now we are moving. But much to my surprise..we have tons of walnet tree's on our new property! I really dont think there is a passing time for ripeness..pluck them off the ground and let them dry.

Black Walnut

My ex-father-in-law give us one that his father brought over from England. A few years back I thought it had died, but it came.

Black walnut trees

I would like to give away about 500 lbs of Black walnuts. It's a shame to just throw them away.

Free Black Walnuts

Hi, I just reassured your comment about having black walnuts. I just transplanted my first and only sapling that maybe a squirrel planted which started me wanting to plant more, and maybe others for eating. I live in a suburb of Cleveland, OH so I’m not sure how I could get them. If you’re not in my area, any ideas how?
Thank you for your consideration,
Keith

black walnuts

I read about someone who ran over the nuts with her car, to get rid of the hulls!

BLACK WALNUTS

My grandparents had a gravel drive and grandpa always put the walnuts in the drive to be "cleaned". Grandkids were then "hird" to gather the nuts. Worked great!

big surpise

Our 27 yr. old son was give a black walnut tree in 2nd grade for Arbor day. We have babied it all these years thinking it would never have fruit! Today, with the leaves gone on it, I was standing under it and saw a green small fruit on the ground. At first (being rather ignorant) I thought maybe after all this care, it wasn't even a walnut tree! Looking up I could see more of these on the tree, maybe 12. I was so excited when I tried to cut into it and found it REALLY IS A NUT! SO EXCITED! How can I get it to have more nuts in the future?

Black Walnuts and Paw Paws

I am fortunate to have several beautiful woodland properties of 12-20 acres in size and I have many black walnut growing on one of them. I also have many Paw Paws growing here as well. I can tell you that these two species live in complete harmony with no ill effects to the Paw Paws whose fruit is just wonderful. In fact the Paw Paws thrive and produce much better in the filtered shade of Black walnut than they do with the other large forest trees such as oak and maple. So, I get a harvest of walnut nut meats and juicy, sweet Paw Paw every year on the same piece of ground and their fruit ripen at the same time.

Black Walnut, cracking

I have tried every method known to man to get into the nuts from my tree. I finally have given up

I recently googled 'Walnut

I recently googled 'Walnut cracker' depending on what you want to pay, they have some nut crackers on the market that may or may not open them easier than smashing them to bits with a hammer. I am going to find out soon!

Tapping Black Walnut for Syrup

We tap our Black Walnut trees in late winter/early spring and boil the sap down. It makes the best syrup, even better than maple syrup!

Black Walnut Tree leaves used as a Flea repellent

In 1993, we were one of the many families that had their homes flooded. When we were finally allowed back into our home, over a month later, we discovered that our home was severely infested with sand fleas. I mean, it was so bad that within a few feet of the door, your legs were covered with them. At first, we called a pest control company, but they wanted hundreds of dollars and they would have to come out and retreat again in about 6 months or so. Then I remembered an old trick my Grandmother taught me. Go out and fill about 3 lawn sized trash bags with Black Walnut tree leaves, then starting furthest away from the doors, begin spreading the leaves on the floor and on any upholstered furniture. Work your way to the door. Wait three days and then vacuum them all up. Now, this is a lot of work and mess, but since we wouldn't be able to live there until the fleas were gone, it worked for us. And we didn't have to retreat anything in the following spring.

The easiest way to remove the husk of the nuts of a black walnut

I had the privilege to learn some my wife the best and easiest way to skin the husk off' a black walnut. Take a pine board long enough lay across a bucket. Drill a one and a half inch hole in the center of the board. lay the board across the bucket and put on a pair of latex gloves. Put the nut over the hole and push the nut through the hole,discard the husk and dry the nut. Try it and avoid the mess.

Removing walnut husks

The hole in the board method is good for smaller quantities of walnuts but if you happen to live in one of the 12 midwestern States where black walnut hulling stations are located you can ask the huller to run yours through for a nominal fee. I have mine run through 50lbs. at a time and they are cleaned off very nicely in about 2 minutes or so. The hulling stations are for processing and selling black walnuts through Hammon's black walnuts. Their manufacturing site is in Missouri where they do the cracking and further processing. These country buyers ( hulling stations ) can be located online by going to : black-walnuts.com. Just click on the Harvest tab and the dropdown will have : hulling and buying locations. Just enter your zip code and you will get a listing of the closest hullers near you.
Good Growing

first time black walnuts harvest

Love hate relationship is a statement beyond measure, after cursing the trees for some 18 yrs. I found out you can actually eat the nuts. So I bought a huller, hair dye gloves., thinking i had to get really elaborate with this harvest. The first round of Nuts that fell from the tree I took off the shell. washed the nuts only to have the whole wheel barrel full of nut float to the top. which meant that the batch I just harvest had no nut inside or that the meat in the nut had not fully develop. ( I tried to get the nuts before turning yuck black). So I waited. then the squires came , Ah, time to harvest. So instead of using the expensive huller, I just stepped on the nut, yuck maggots. ( That is the another reason I wear the Gloves.) Hosing off all the yuck, My first batch of the first harvest is drying. We have a lot of black walnut trees. A few wheel barrel full works for me. The trees are about 70 to 100 year old. I'm looking forward to adding the nuts to fudge, stuffing, and giving some to friends and family.
Such a wonderful blessing , that was once a curse. But what a mess.

Black walnut

Beware that black walnut trees are known to be toxic to horses. They provide great shade but should not be near a barn or in/near a pasture

Black walnut

Beware that black walnut trees are known to be toxic to horses. They provide great shade but should not be near a barn or in/near a pasture

All the walnuts.

I can't even count how many walnuts I have ate over the years, and when I moved in with my wife on the farm get grandparents left her they have a big black walnut tree. I was so happy to see it, however it had been a long time since I helped my grandpa throw walnuts into the driveway to crack them open when people would run them over. I had completely forgotten how to harvest them, and then work and bills and many didn't name it a priority. But after reading this post I want to remember the old days and practice them, so I'm heading it to get walnuts now. Thank you for bringing back such great memories.

Black walnut trees

I live on an old farm in SE Ohio that's got black walnut trees everywhere. I get truck loads of chipped wood from my utility company when they're working in the area trimming trees, & use that for mulching flower beds. At one point the chips were such a light color that I learned to make walnut stain - but haven't used it because I wasn't sure if it would harm my hostas & other plants? The easiest way to husk them (if you don't want the nuts) is to leave them outside overnight - the squirrels will do the work & take the nuts, leaving the husks needed for stain. Put the husks in a bucket, add water & let them soak a day or 2, then scoop the hulls out & dispose of them. My rule of thumb is 15 walnuts per gallon of water. A faster way is to boil the husks in water for an hour, then strain the husks out. OR you can dry the husks & grind them into a powder that keeps more easily, making stain when you need it, 1 oz of powder to 1 qt of boiling water. My squirrels really get a messy job done with no complaints!

"Threatened by few pests"

Our attempt at growing a black walnut was thwarted by our local deer herd who annually pruned our small tree until it looked like a 6' broomstick. The last year when it leafed out it split in 3 segments from the top down about 2 feet. End of tree and story.

burning the black walnut trees, is it safe?

my nieghbor cut down his tree and wants to know if its good to burn.

Burning Black Walnut Tree

Yes, a black walnut tree is fine to burn. It’s not toxic to humans. It splits easy and burns hot and long as long as it’s seasoned properly. 

Black Walnut

I prefer oak or hickory. I have burned black walnut but it does not seem to burn hot and even after a year of seasoning does not burn well. I would have to mix some oak with it to get it to burn. That wood is not worth the trouble if you have an alternative.

Black Walnut trees

I started a walnut sapling this spring by accident. Gathering and sorting the fruit for harvest and compost, I threw down this one nut in a shrub bed that I didn’t want to bother with and has been growing well since sprouting
As much as I’d like to patiently wait on this tree to bear fruit and shade, I have no yard to speak of with which to grow it and besides, I may be on to a more immediate use for this handsome wood if it’s so easily worked.
Question:

Black walnut

I have four very mature black walnuts, one of them in the open was massive when I moved in 20+ years ago, now it is gigantic and taking over the yard, I started lopping off a few branches that were Getting too close to the house, my question is the tree is on a slight tilt, it looks like some straight winds from a storm years ago slightly moved it. The branches that I removed we’re on the opposite side, are the root systems very strong? I’m not worried at this point about the tree falling, But do trees naturally balance themselves, Some of these branches on this walnut are the size of other large trees

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