Saving the Butternut Tree

An Invasive Fungus Has Infected Almost the Entire Native Population In The N.E.

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Forest Pathologist Dale Bergdahl is an expert in the butternut tree and the canker that's killing the species
Photo:Jane Lindholm
Forest Pathologist Dale Bergdahl points out a canker on a diseased butternut tree
Photo:Jane Lindholm
Kathleen Osgood Dana's huge butternut in Northfield, Vermont. The tree is slowly dying due to butternut canker
Photo:Kathleen Osgood Dana
Kathleen Osgood Dana's huge butternut in Northfield, Vermont. The tree is infected with butternut canker
Photo:Kathleen Osgood Dana
Saving the Butternut Tree
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Saving the Butternut Tree

The butternut tree, which is native to the northeast, is difficult to find these days. Like with Dutch elm disease and the chestnut blight, an invasive fungus is killing the species.  As part of a collaboration with northeast stations, Vermont Public Radio’s Jane Lindholm reports on efforts to save the butternut.

Kathleen Osgood Dana walks into the forest surrounding her home in Northfield, Vermont. She stops in front of a huge tree stretching high above the forest floor.

“This butternut was here when my family moved here in 1956.  And the butternuts dominated this entire hill so my father named it Butternut Hill.”

As a child, Dana collected the nuts to make maple butternut ice cream. And her kitchen cabinets are made out of the hardwood. But over the years she’s watched this tree—like others on the hill—slowly die.

“If you look up this left trunk, see it’s still trying to make some leaves up there. But this right trunk has died entirely. You look up and it’s all dead.”

What’s killing Dana’s butternuts is an invasive fungus that has infected almost the entire native population east of the Mississippi.

Vermont Forest pathologist Dale Bergdahl is an expert on the disease, called butternut canker. Pointing to an infected tree in a park in Northern Vermont, he says the disease is easy to spot.

 “You’ll get these areas of dark discoloration, kind of like soot, on the bark, oozing from these areas of infection. A single canker’s not a big issue…"

But over time, multiple cankers surround the tree and essentially strangle it. Bergdahl and a team of scientists from around the northeast are trying to develop a new strain of butternut that will resist this disease. Like a detective, Bergdahl is searching for the few butternuts that are still thriving, despite the disease. He travels all over New York and New England taking samples. But it turns out identifying a butternut tree isn’t so easy. Sandra Anagnostakis, a scientist at the Connecticut Agricultural Experiment Station is one of the researchers working on the restoration project.

 “What we’re finding is that in Northern Vermont, most of the trees are butternut. The further south we get, say in Massachusetts, half of them were butternuts and half of them were Japanese walnuts or hybrids. In Connecticut, almost all the trees were hybrids or Japanese walnuts.”

The reason for the discrepancy could lie in economic differences that once divided the region. In the 1800s, Americans began importing Japanese walnut trees. The walnut is easier to crack than the butternut. But northern farmers couldn’t afford these trees.

 “Whereas anybody who was in the affluent New York, Connecticut, New Jersey area probably would have seen trade magazines with advertisements for Japanese Walnuts and heard the raves about what wonderful trees they were and would have been apt to spend their money on getting a few of them.”

The hybrid offspring of those walnuts are now making scientists’ job more difficult.  All butternut samples have to be sent to a plant geneticist for identification. When they find a pure butternut, scientists graft its branches onto black walnut root stock. If these new seedlings can resist the deadly butternut canker, they will be bred into super butternuts that can begin to re-grow the population. But Anagnostakis says that will take at least a decade.

 “Well, you have to think in tree time here. Nothing to do with trees is ever very fast.”

Back in Northfield, Vermont, Kathleen Osgood Dana is willing to wait. Samples from two of her remaining butternut trees were taken last winter.

 “I don’t know that any of the materials that we have from these living butternuts are going to be any good. But if they are, that’s a legacy.”

A legacy she hopes will continue on her property on butternut hill for her grand kids to enjoy.

Northeast environmental coverage is part of NPR’s Local News Initiative.



Want uncracked butternuts

I would like to plant and taste butternuts. If you have a tree, please contact me to arrange a delivery or sale.

send/sell me some butternuts?

I would like to purchase some uncracked butternuts for seeds and tasting. I can be reached at Thanks

I have a butternut tree in my

I have a butternut tree in my back yard. I always thought it was a black walnut (I have three of them ) until this year when the nuts appeared for the first time. We live in western Pa. I plan to harvest the nuts in the next month or so.


I lived for some 15 years against a woods that contained what I identified as butternuts (white walnuts), in addition to 300-year-old oaks and slightly less mature cherries and scrub maples. Every May, the butternuts would blossom for a week with white flowers, and the air was fragrant with their bloom. About five or six years ago, they stopped blooming.

My woods contained many standing dead butternuts during my stay, which I harvested for fuel for my stove--the wood was hard yellow, tough as dogwood, and gave a challenge to the chainsaw.

Although 90 percent of my at least 50 butternuts were dead or dying and thus no rounder than a 10-inch diameter, I had one that had [has] a four-trunk structure and reaches about 70-80 feet, with a thickness that would belie the common wisdom that butternuts live about 75 years.

This was and (I hope still) is in New Jersey.

When I traveled to Cape Cod, I was told by a brush-clearing contractor (for the adaject property) that the same butternut saplings (about a 5- to 7-inch diameter) that I found on my property in New Jersey (along with my Grandpa Butternut) were in fact black locust "vines"--that they were pernicious and had to be mowed down. (I said, well okay, but could you save me that wood for burning?) Further research indicated that the black locusts he was pointing out--when they are saplings--resemble the butternut in structure and leaf.

In fact, on my own property, I found these true black locusts, replete with thorns, hiding in the boxwoods. They indeed looked like young butternuts.

So my query of this post contribution is twofold: (1) should you contact me to see a butternut tree that is more than 75 years old in a butternut grove, and (2) should you help me be able to tell an expert that he's cutting down butternut saplings and not the dreaded locust "weed" that Cape Codders say is a scourge?

Thank you.

butternut tree

Ilive in eastern KY and a friend of mine has a huge butternut tree on his old homstead it does not appear to be infected with kanker sores or any other dieseases. iwould like to help save this type of tree. so if there is any thing i can do pleasem let me know. the tree is over 75 years old (my friends father told me when he was a child the tree was there and he recently died at age 75.)

butternut tree

Yesterday, we saw a butternut tree hidden behind the Shakers' herb drying house in Harvard MA. The guide identified it but asked us to google it. The tree was bearing green round fruit. I had seen walnut trees but this was the first time I had heard of butternut trees.
Someone in the group mentioned that the butternut yellow color on the British soldiers' uniform in the 18th century originated in the butternut. This has not been confirmed.

Mold on butternut walnuts

A friend recently gave me a large bag of walnuts. My husband put them in the garage and after a couple weeks of damp weather I checked on them and much to my dismay the dampness had gotten to them and mold was covering them. Do I need to throw them out?

I hope this works.

I hope this works.



Hi, Randy! We'd love a photo!

Hi, Randy! We'd love a photo! Please send it to, address it to our local environmental reporter, Nancy Cohen. Thanks so much!


I have several young butternuts on my land that I just purchased last year. Some have cankers and others don't. They continue to grow fine this year. I searched for the parent trees for some time before finding a small cluster of about a dozen of them on a part of my land that I had yet to explore (we have 75 acres) It was spring time when I was back there, it looked as though the largest of the trees was blown down but still alive. This weekend I plan to return to see if they have cancers or not. I have also found a healthy butternut in winooski VT that I spotted from I89. It about 40-50ft tall and looks great! If you like I can take pictures and you can decide if it's worth a visit here.



Questions about identification or disease can be sent to me, and I'll try to answer.

Sandra Anagnostakis

Re: restoration of the butternut trees in New England.

We have a butternut tree that was planted here in Sanford, Maine, 40 years ago by my mother who was in her 70's at the time. This seedling came from her parents farm in Porter, Maine where they were plentiful. There are 2/3 more on our street which were there when we moved to the area in 1963. Our butternut bears nuts every year but has, practically, from the beginning had a brown fungus/wilt which develops on the leaves shortly after it leafs out. The leaves always drop prematurely. I contacted the University of Maine Extension Service about this a few years ago and they suggested that just about the only thing we could do for this fungus is to try and clean up the fallen diseased leaves every year to prevent reinfection, but that was not practical in our case so after a couple of years we stopped doing it. I really don't believe this tree is infected with the canker as described in the article. I have observed this condition in some Autumn Olive trees we had at one time so I think I know what it looks like. In spite of the fungus condition, the tree is growing quite robustly and we frequently find seedlings sprouting in the yard which were, no doubt, a result of gray squirrels storing up food for the winter. I would be interested in your opinion as to what we might do to rid it of the fungus (not sure that this is the correct term to descibe the condition). Also, thought you might be interested in their existence.Thank you. Vaughn Watson, Sanford, ME