Black Walnut Trees

Facts and Features of the Black Walnut Tree

George and Becky Lohmiller
black-walnut-trees-roots-evil-ascending-the-giants-wikimedia-commons
Photo by Ascending the Giants: Wikimedia Commons

The black walnut tree is one of North America’s most valuable and beautiful native trees, but it does have a “dark side,” too. Here’s what you should know before planting a black walnut in your yard!

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 that inhibits many plants’ growth. 

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.

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.

Reader Comments

Leave a Comment

Black Walnut Tree

Our black walnut tree is very productive. Much more than the English Walnut. However, the nut on the black walnut is very small and do not taste nice at all. Is this normal for the small nut? It is almost not even worth collecting, shelling and going through all the process. Can you shed some light in this issue. Thank you

A Hard Nut to Crack

Hi, Cassandra: Black walnuts can indeed seem to not be worth the trouble—but they are! It sounds like you’re not curing your nuts. Wash and dry them, then leave in a cool, dry place for 2 to 3 weeks. We think you’ll find them much improved. Thanks for asking!

I have a walnut tree that needs to go.

She is about 40 feet tall and about 15 feet of straight trunk. I live in Columbus Ohio. Cut it down, clear it away, and grind the stump and it's yours.

Walnut tree

Hi Jason,

Is your walnut tree still available? I might be interested in it. My number is 330 447 1780

green leaf defoliation

My walnut tree defoliated all green leaves en masse. I came home from work to find almost every leaf on the ground. I live in Michigan. Anyone else experiencing this? I didn't see sign of disease in the leaves.

Worried about my black walnut tree

We just bought a house in the early summer of this year. There is a huge black walnut tree out back that we just love. I've noticed recently that there is what appears to be moss growing all over it. Is this normal? We really love this tree and don't want to lose it. Please help.

A Mosstery

Hi, Jamie: This really calls for a local arborist, as we don’t know where you are, and even if we did, you don’t say whether “growing all over it” really means what it says, i.e., bark, leaves, everything. And we assume that this is not just lichen growing on the bark. Black walnuts are susceptible to a whole range of pests and diseases, including thousand cankers disease, so it is best to get a professional diagnosis ASAP so that you can begin treatment likewise. Thanks for asking, and good luck!

walnut tree bumper crop

Here in SW Michigan. Our tree has never produced so many walnuts as this season. A friend told us of a conversation he had years ago with an old farmer. He said a heavy drop of walnuts meant a hard, bad winter.
Anybody heard this? Trying to decide how much time to spent in Florida!

This Must Be Nuts

Hi, Scott: Thanks for relaying this info. Yes, there is a lot of folklore surrounding what are called “mast” years, when there seems to be an overabundance of nuts and fruit, as though the vegetable world could sense that the animal world was going to need more food during the upcoming winter. Our forecast for your neck of the woods calls for a winter that is not quite so cold as normal but with plenty of precipitation, much of it not in the form of heavy snow. Thanks again!

no nuts this year

I live in Central Michigan. Last year was a heavy production. This year hardly a nut was to be found. If what you heard is true, I'm hoping my tree is the predictor.

Black walnut trees

I love our trees, unfortunately they have contracted the Thousand Cancre Disease , which my arborist says there is no cure for, and that we will lose them all , I have at lest nine in my yard. I live in Colorado.

I hate my tree

My black walnut tree was there when I moved into my house. I'd cut it down but it's too expensive. If anyone wants the wood pm me and you can have for free if you cut it down!

Hate ours too

Hate ours too

Love the wood

Where are you located?

Black walnut

I’m located in Lexington ky 40509 and will travel any distance I have a trucking company so distance isn’t a problem

Black walnut trees

I have a few black walnut trees if your interested. Trunk circumference is 3-4 ft.

Have two walnut trees for removal

I have two walnut trees I would like removed (for free -- wood is payment). One is about 3 feet & other 5 feet in circumference. (Have a bumper crop of walnuts this year and I'm tired of it.) If interested, I'm in Maryville TN, 37801. Thanks for your consideration.

Want to buy your black walnut tree

Someone in the last discussion said they hated there tree and there’d give it away if I’d come get it

I have a big walnut tree in

I have a big walnut tree in my front yard live in Cincinnati send me your contact information If you’re interested it’s more of a hassle than anything!

Anyone hate these trees out west?

Yall are all out east, if I lived within 500 miles of any of those offers I would be all over it (but honestly though, black walnut wood is really valuable, don't give it away for free, that sells for anywhere between $11 and $18 a board foot)

I have a big walnut tree in

April, Is this tree still at your place, how close is it to your house?

Leaves

My 3 black walnut trees only 1-1/2 years old are getting black edges on the leaves also have a English walnut no problems

Large Black Walnut tree dropping large to huge branches

In the past two weeks, we have had 3 branches break off and fall off the 40 foot black walnut tree in the back of our yard. The branches were full of green leaves and walnuts. In fact, as I was collecting nuts for a friend, and clearing them from the back yard so hubby could cut the grass, a branch broke and fell on top of me! Thankfully it wasn't as big as some of the others that have come down, but now I am very cautious about going under the darn tree. We have lived here 20 years and I have never seen this happen. The branches seem to be splitting. I cannot find much help on the internet, and saw that this site was at least current. Hubby thinks this is because the nuts are plentiful and too heavy for the branches. I am not so sure. Any advice would be greatly appreciated.

Walnut Branches Breaking

If the amount of walnuts is truly significant—especially closer to the tips of the branches—the weight could cause smaller branches to snap off the tree. However, we would wager that you are probably looking at a pest or disease issue. There are a number of diseases, such as thousand cankers disease, which can weaken the tree and result in broken branches. We would suggest contacting your local Cooperative Extension Service and inquiring about what diseases are known to be present in your area. Pictures of the tree and the broken branches will help them ID the issue, too.

Don't plant near your home or driveway

I have a huge black walnut tree on a small city lot. It is beautiful and provides shade to me and three of my neighbors; all of whom complain about the tree everytime we talk. I refuse to cut the tree down because it is well over 100 years old and it is beautiful; but, it makes a mess of my cars, driveway, yard and roof. My roof and driveway are covered with black stains from where the walnuts fall and break open. The tree drops little droplets of a sap like substance that doesn't easily wash off. I have not been successful growing anything beneath this tree, with the exception of tulips. Seriously... Wait until you get hit in the head by a falling walnut, it's no joke, they come down hard and fast! But, like I said, it's beautiful and old and healthy and I can't bring myself to cut it down.

If you're going to plant one, I recommend keeping it away from your house, decks, driveways, etc. Or, if you don't like your neighbors, plant it near the property line and 20-30 years later you'll have a blast hearing them complain about it all the time!

Black walnut tree nuisance

Don't plan these tree unless you want problems! My neighbor has one on our property line next to our garage in a small city yard. The nuts sound bombs when they fall. The squirrels open up the nuts and leave the shells all over and they stain our driveway, deck and furniture. I am afraid of being hit in the head by these nuts which are extremely hard like a golf ball but are large like like a kiwi. It's dangerous to be near this tree. Also, once thel broken shells dry, they are sharp so forget about walking barefoot in your own yard. Now a raccoon has build a nest in the neighbor's nightmare tree. Not to mention the damage the roots did to my concrete sidewalk and garage floor. I could go on and on but do yourself and neighbor s a favor, don't plant a black walnut tree and be diligent about getting rid of all weed trees on property lines. Trust me you are not going eat these nuts.

I have NEVER seen a raccoon

I have NEVER seen a raccoon build a nest in any tree

Black walnut trees

We had a beautiful black walnut tree in our back yard, but Dad had it cut down because it was killing everything else he wanted to grow back there. But the wood did make a gorgeous cedar chest. The finished wood looked like gray to black velvet. The gray just faded into small areas of dark and back again. Oh was it gorgeous.

Black Walnut Tree

After we have cut down our black walnut trees we want to plant maple trees near their stumps.

Is this a good idea.

replacing a black walnut tree.

what trees can we plant where our black walnut tree was?

/

Pages