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Trees on the Roof

Friday tree fact: the courthouse tower groves of Greensburg

The town of Greensburg, Indiana, is known as the “Tree City” for the over-a-dozen trees that have been growing out of the roof of the Decatur County Courthouse serially for 145 years. (They’re believed to have sprouted from seeds in bird droppings.) In 1870, the citizens of Greensburg began to notice what looked like a small sprig growing on the northwest corner of the courthouse tower. No one paid much attention to it at first, but as the shrub grew into a young tree, it became the talk of the town.

Some years later, five new sprouts were spotted on the tower roof, threatening to form a small grove atop the 110-foot-tall tower. Authorities were worried the tree roots might cause irreparable damage to the roof, so in 1888 a steeplejack was hired to cut down the smaller trees – file under climbs we wouldn’t particularly want to make –  leaving just one tree, which in time grew to about fifteen feet with a diameter of almost five inches at its base.

The tree continued to brave the storms for many years, until it finally died and was removed to a place in the Decatur County Historical Society Museum – but that wasn’t the end of the (now famous) courthouse tower tree. In the interim, another tree had appeared on the southeast corner of the tower, and grew to a considerable height in just a few years’ time.


photo via ntime60@flickr

According to some reports, the courthouse tower grows new trees constantly, and steeplejacks must climb up periodically to remove them and trim the main tree. When this gets too old or diseased, it is removed, to allow another growing tree to take its place.

The species to which these trees belong has been a matter of debate for some time. Some believed the trees were lindens, others that they were of the silver poplar variety; a scientific classification by the Smithsonian Institute established they were actually of the large-tooth aspen variety. That solved the mystery for a while – until 2007 when several foresters from Purdue University firmly identified the current tree as a Mulberry tree.


img via houstonian@flickr

No definite explanation as to how the seeds of the first trees found their way to their lofty germinating place has been found.

Regarding the matter of sustenance, most theorists believe that dust from the interior, as well as dust and moisture from the outside, does the trick. No one is sure – but when somebody suggested that the tree was fed by springs in the clock, a citywide ban was placed on all tree jokes. (aw, shucks!)


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