Catalpa — the ultimate fence post?


Have you ever heard of a “fence-post tree”? Also known as Indian bean tree, cigar tree, catawba, or caterpillar tree, Catalpa is a large tree with showy white, fragrant flowers, massive heart-shaped leaves, and dangling bean-like seed pods on a twisting trunk and contorted branches. First cultivated in 1754, Catalpa was briefly popular for fence posts and railroad ties due to the tree’s fast growth rate and resistance to rot. Catalpa trees are plentiful on our farm, first settled in 1848. At some point in the farm’s history, rows of Catalpa trees were planted along the lane and around the farmyard.

During the settlement era, good, economical fences were some of the most important tools for taming the frontier. Crops had to be protected from hungry cattle, horses, and hogs, and prized livestock had to be fenced in to prevent breeding with inferior bloodlines. Virginia Rail or Snake Rail fences, built with logs split lengthwise into narrow rails, produced effective fences but used a lot of wood. Around this same time, Joseph Glidden and Isaac Elwood patented barbed wire fencing.

Glidden and Elwood’s barbed wire fencing replaced the tried and true Virginia Rail fences, but the wire still required wooden fence posts, a LOT of wooden fence posts. Meanwhile, railroads were pushing westward, consuming 3,520 crossties per mile. White oak and American Chestnut made the best ties, but both were slow-growing trees. Since common Catalpa grows much faster, these famously untidy flowering trees were the focus of an intense effort to find a fast-growing alternative.

Enter catalpa evangelist Robert Douglas. Already vigorously promoting catalpas as great for railroad ties, he quickly added posts for barbed wire as an additional use for the trees. The trees Douglas was touting were the Catalpa speciosa, commonly called Hardy Catalpa. Unlike its closely-related southern cousin, Common Catalpa, Hardy Catalpas grew quickly with straight, tall trunks often 80 feet high. Common Catalpas have short, broad, contorted trunks of extremely soft, light, brittle wood that is useless for fence posts, and for just about everything else, for that matter, including firewood.

Hucksters fanned out across the Midwest, selling bundles of bare-root Catalpa seedlings to farmers eager to produce their own fence posts. Unfortunately, it is almost impossible to tell the two Catalpa breeds apart from their seeds and seedlings. Even more unfortunate was the tendency of Hardy Catalpas to instantly crossbreed when anywhere even moderately close to Southern Catalpas. Also unfortunately for farmers, unscrupulous Catalpa salesmen cared not whether they were selling Hardy or Common seedlings.

It took years for victims of this switch to discover they’d been cheated, long after the salesmen got away with their money. I believe that our farm’s former owners made the best of this situation by simply planting sapling Catalpas twenty feet apart, and then stringing barbed wire between the live trees once they grew strong enough. Problem solved.

Some of these original trees, gnarly and battle-scarred, survive to this day, and the seed that scattered from their pendulous pods has established younger generations of Catalpas throughout our woods and fields. Sole host of the catalpa sphinx moth, they are also very popular with woodpeckers, hummingbirds and bees. One hollow Catalpa in our barnyard is home to a honeybee colony.

Like most “fast-growing shade trees”, Catalpas have drawbacks. Though very adaptable to adverse conditions, they have weak wood and a brittle branch structure, and drop rotten limbs constantly. Each spring they bloom profusely, showering us with big, sticky petals. Next come the Catalpa worms; a boon to fishermen but a real nuisance as their scat covers everything under the trees. Hard frost brings another shower, this time giant sloppy leaves which drop all at once. All winter long the catalpa “beans” drop their seeds and then their husks.

While it may not be an ideal tree for every location, Catalpa is a unique, hardy, fast-growing tree that is widely grown on residential properties, parks and other open spaces throughout the country. We view ours affectionately; historic reminders of an earlier day, worth preserving. Their very imperfection endears them to us.


By Steve Boehme

GoodSeed Farms

Steve Boehme is a landscape designer/installer specializing in landscape “makeovers”. “Let’s Grow” is published weekly; column archives are on the “Garden Advice” page at For more information is available at or call GoodSeed Farm Landscapes at (937) 587-7021.

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