Ash trees—strong, elastic, versatile—have been used to make everything from handles for Neolithic tools to the rim of a wheel found in King Tutankhamun's tomb to modern baseball bats. But now an invasive beetle called the emerald ash borer threatens the existence of the trees that people have been depending upon for thousands of years.

For his book The Man Who Made Things Out of Trees, Robert Penn set off across Britain and beyond in search of craftsmen to help him fashion an extraordinary variety of artifacts—including a toboggan, a hurling stick, and a Louisville Slugger baseball bat—out of a single mature ash tree. He spoke to National Geographic about the importance of these imperiled trees from his home near Abergavenny, Wales.

View Images Image courtesy W. W. Norton

Your search for the perfect ash began near your home along the Welsh-English border. Set the scene for us—and explain how you went about finding the perfect tree.

I grew up under an ash tree. It has been my favorite tree all my life and, in many ways, it’s been a lodestar that has guided me on my journeys around the planet. It led me to live here in South Wales, in a landscape that is heavily accented with ash. After I moved here from London 15 years ago, I got involved in managing a woodland in a place called Strawberry Cottage Wood a couple of miles from my home as the crow flies. Through that, I became very interested in where we’re at in our relationship with trees at a local, personal, and global level.

To find the tree I was looking for, I looked at Google Maps and my old Ordnance Survey maps, then rang the farmers I knew and went to look at their ash trees. But none of them suited. Slowly, I drifted farther away until I found the tree I was looking for in a wood called Callow Hill Wood, next to the village of Ewyas Harold, on the English-Welsh border. The wood belongs to the Kentchurch estate, which has been in the Scudamore family since 1040. The ash tree I found was 125 years old, which is pretty good for an ash tree.

In America, white ash plays a key role in the country’s national sport. Tell us about your trip to Hillerich & Bradsby in Warren, Pennsylvania.

There are 16 or 17 species of ash in North America. In the 1920s, ash became the most popular wood for baseball bats until the 1990s when Barry Bonds, the great American hitter, swung a maple bat, which started a craze for maple. But, whereas ash will tell you it’s going to crack or split before it actually does, maple can break in a very explosive way. There were even instances of shards of maple bats hitting umpires, fielders, and even members of the crowd.

View Images Ash is still the wood of choice for baseball bats. Before the 2013 World Series, Kevin Olges worked on the bats at the Louisville Slugger Museum & Factory. Photograph by Andy Lyons, Getty Images

I went to Hillerich & Bradsby’s sawmills in the woods of the Allegheny Mountains in Pennsylvania. Because the Louisville Slugger is such an iconic brand, I assumed that the sawmills would be on a really grand scale. Actually, it was very hokey! [Laughs] And rather delightful for that. There was a degree of mechanization but basically it was a group of good old boys who really care and understand what goes into making a great piece of ash timber. So much of the process, from standing tree to a finished bat that’s going to be swung in a World Series game, is about eye and human intuition and an innate understanding of the properties of this remarkable wood. And almost everywhere I went on that journey it was the same thing.

Across the Atlantic, in Ireland, ash is also used for an iconic piece of sporting equipment. Tell us about "the clash of the ash."

It’s the nickname of this remarkable game called hurling, which is thought to be the oldest field game on the planet. It’s also a rather beautiful game, played with a wooden stick and a small ball, and that stick is made from ash. It’s been described as a cross between ballet and homicide. Or hockey for people who don’t care about their teeth. [Laughs]

It is a bit like hockey but the ball is airborne most of the time. It’s incredibly fast and furious—and elegant. Lots of other species of wood have been experimented with as well as man-made materials like plastic or carbon, but time and again the players go back to ash. They talk about the way it feels in the hand: how a wooden stick teaches you as you’re learning the game, whereas a stick made from man-made materials doesn’t.

View Images In Ireland, the sport of hurling is known as "the clash of the ash." Here, Kilkenny battles it out with Tipperary at Croke Park in Dublin. Photograph by Brendan Moran, Sportsfile/Getty Images

Ash has played a significant role in sport over a very long period of time. Native American Indians used ash to make lacrosse sticks before the Europeans arrived. Squash rackets, snooker cues, and the famous Dunlop Maxply tennis racket were all made of ash. Tennis aficionados say that the last all wooden racket Wimbledon final in 1980, between McEnroe and Borg, was the greatest final ever played. There is something about playing a sport with a natural material that makes it more refined and elegant.

We have mentioned sporting equipment. But ash has been used to make an extraordinary variety of things, including even cars, hasn’t it?

The list is endless: ladders, boat hooks, looms, crutches, umbrella handles, bell stays in church towers, catapults, and arrows. When Henry V went on his famous campaign to France in 1415, which ended at the Battle of Agincourt, he took three million arrows made of ash with him. And they played a decisive role in the English victory.

View Images In Britain, the Morgan Motor Company still builds all of its sports cars on an ash frame. Photograph by Simon Dawson, Bloomberg/Getty Images

From the time of Neolithic carpenters until the middle of the 20th century, the majority of the tool handles across the northern temperate region were made of ash. From ancient Egypt until the end of the horse age at the beginning of the 20th century carpenters made the rims of wooden wheels out of ash. When cars first came along, the bodies were made of ash. The Morgan sports car is still built around an ash frame because the manufacturer believes that it has properties no other material can match.

What makes ash such a versatile wood?

It has distinctive properties that no other tree species matches. It’s strong and of moderate weight, which is important with respect to a tool handle or a piece of sports equipment. It is easily steam-bent, which is important for skis or tennis rackets. It cleaves and splits easily down to the size of the end item you want to use it for. Perhaps most importantly of all, it has an elastic property that no other tree species has. That’s why Neolithic carpenters preferentially used it for tool handles 4,500 years ago. They’d experimented with oak or beech tool handles, but what they came to understand was that ash broke less often. That is why it has been a strategic necessity and a driver of the advancement of our species for so long.

View Images Robert Penn, shown here splitting wood near his home in Wales, made 44 different artifacts, including a baseball bat and a desk, from a single ash tree. Photograph by Adrian Sherratt, Camera Press/Redux

You managed to make an incredible 44 different artifacts from your ash tree, including the desk at which you wrote this book. Talk about some of the craftsmen you worked with.

The loveliest thing about writing the book was coming into contact with the different craftsmen. The one who stood out for me was Phill Gregson, a fourth-generation wheelwright. His father was a wheelwright and even his mother, until she gave birth to him. According to the great census of Great Britain and Ireland in 1911, there were over 23,000 wheelwrights working, just before the end of what came to be called the horse age. He is now one of the last half dozen or so wheelwrights making a living in Britain from it.

Spending time with Phill was fascinating for a number of reasons. Most significantly, I realized that so much of what he knows is not written down anywhere. By the time I met him I had read most of what I could find about wheelwrighting. But in the course of one morning with Phill, I came to understand that his knowledge about the properties of ash was passed from master to apprentice, father to son, in the same way that folk songs were for hundreds of years. And it would be a terrible shame if that knowledge gets lost.

View Images Because of its elasticity, ash has been used since time immemorial to make wheel rims, like these found in the tomb of Tutankhamun. (Photograph by Stapleton Collection, Corbis/Getty Images

I watched him make a wooden wheel, for which he used some of my ash tree. He uses ash for the rims, oak for the spokes of the wheel, and hardwood for the hub. The way he uses these timbers is pretty much the same as the Egyptian carpenters who made the wheel found in the tomb of Tutankhamun. We live in an age now where everything has to be new. The mantra of so many of us is, “Have you got the latest version of the iPhone?” But the beauty and greatness of human experience lives in the continuity of understanding between us and natural materials.

The ash faces enormous challenges today. Tell us about the emerald ash borer—and why it’s so important to save this tree.

The greatest threat to the ash tree is something called the emerald ash borer, which is a rather exquisite, metallic green beetle that co-evolved with ash species in Asia. It was introduced accidentally to North America in 2002, most likely in a packing crate imported from Asia. That beetle has now worked its way through quite a large part of the continental U.S. and is in Canada. It is estimated that there are 7.5 billion ash trees in the timberlands of the U.S., plus some 30 to 90 million ash trees planted in urban areas. So far, the beetle has killed over 100 million ash trees and, I’m afraid, every single one is now under threat despite the fact that well over $200 million has been spent on trying to eradicate or even slow the pace of the progress of the beetle. It is remarkably voracious.

View Images The emerald ash borer, an invasive species from Asia, has already killed hundreds of millions of ash trees in North America and is spreading through Russia and continental Europe. Photograph by Jeff Wheeler, Minneapolis Star Tribune/Alamy

It hasn’t got to Great Britain yet, though it’s in continental Europe and is thought to now be in Russia and Scandinavia and heading this way. What this means is that the landscape of North America, Great Britain, and continental Europe will be dramatically changed over the course of the next 100 years by this beetle.

Seeing trees die in your landscape is deeply upsetting for people who have grown up with those trees. I am getting emails from people in North America telling me that the ash trees are dying on their property. It’s very difficult to know what to do about it and be optimistic. But we need to improve plant biosecurity internationally and improve our knowledge of plant pathology. We got very good at it at one point in the 20th century but we have let it go rather slack. It’s not just the ash tree. Lots of species are being affected by the global movement of pests. So, if we want the landscape to look the same in the future, we need to value our trees more.

This interview was edited for length and clarity.