Chestnut Trees in Our Backyards? Maybe Some Day

By Bill Lawyer

I recently spent twelve days hiking about 140 miles from Porto, Portugal, to Santiago de Compostela in Spain. In that time I must have awkwardly stepped over at least a 1,000 nasty chestnut “balls”. Their outer coverings are also commonly known as burrs.

Technically, the covering of the chestnut nut (actually a fruit) is a spiny, leathery <cupule> two to five inches in diameter. Along with sweet gum and horse chestnut balls, they are among the least pleasant tree fruits to walk on. But you can’t easily avoid chestnuts along the woodland trails in Portugal and Spain, as they’re everywhere.

That’s probably why Portugal is the seventh largest exporter of chestnuts in the world, despite it being one of the smallest countries (112^th).

Around here, you could walk for hundreds of miles and only find one small place (about three acres) where chestnut trees are growing. And that’s a site on Westchester County’s Lasdon Park property in Katonah.

This wasn’t always the case. When European settlers came to our area, they found the forest teeming with chestnut trees. These trees didn’t have to be planted and nurtured; they functioned quite nicely on their own. Biologists have estimated that in the early 20^th century there were some 4 billion chestnut trees in the United States.

Native Americans and colonial settlers used all parts of the trees — for lumber, food, fuel, fencing, tanning, shingles, furniture, and many other products. The nuts were an important food for wildlife such as jays, pigeons, wild boar, deer, and squirrels.

Chestnuts were made popular in literature and poetry as a symbol of living an upright, sturdy lifestyle. Longfellow’s “The Village Blacksmith” sets that tone in his first stanza:

<Under a spreading chestnut-tree

The village smithy stands;

The smith, a mighty man is he,

With large and sinewy hands;

And the muscles of his brawny arms

Are strong as iron bands.>

But by the early 1940s nearly all the country’s population of chestnut trees was destroyed. How did this happen? In two words, the cause was what is known as the “chestnut blight.” It came into the United States from Asia around 1900 through what they call “nursery stock.” Slowly but steadily the blight made its way around the entire country, leaving just a few stands of American chestnuts intact.

The blight is a fungus that produces spores that are spread from tree to tree by the wind. Cankers caused by the fungal infection cause the bark to split.

The fungus enters through wounds on susceptible trees and grows in and beneath the bark, eventually killing the cambium all the way round the twig, branch, or trunk.

While not all trees die, the fungus causes them to lose their main trunk and branches, leaving just some shoots to grow back for a few years then start the cycle over again.

Chestnut trees are so rare around Westchester County that when I first saw some of the spiky shells on the ground in Portugal I had no idea what they were. It was only thanks to our trusty iPad that we were able to look up the Portuguese name and translate it into English.

But things are actually looking up for the American chestnuts.

Westchester County’s program to bring back chestnuts is part of a much larger project, being developed under the leadership of the American Chestnut Foundation. The Foundation conducts basic and applied research to develop a blight-resistant American chestnut tree for reintroduction back into forest ecosystems within the native range of this species. That’s what is going on at Lasdon Park.

So it’s very likely that in the years ahead, when we go out for a walk, we may be able to pick up some chestnut balls from nearby trees, remove the shells, and take the nuts home to become part of our next meal — right from our own backyards.