The Sw. Jana Tree of Heaven

Ulica Swietego Jana runs from the Main Square to the Planty, one of the most walked streets in the Old Town, and the tree registered at number 30 is a species most European cities spend money trying to remove. Ailanthus altissima, tree of heaven, seeds into any crack in the pavement, sends up suckers under paving stones and shades out whatever grew there first, fast enough to reach a serious size within a single lifetime. Krakow protects this one anyway, entered onto the natural monument register in 1997 for a trunk 292 centimetres around. That speed is exactly why no age is published here. A growth factor that works for an oak or a lime tells you nothing about a tree that can add a metre of height in a good year. Dublin's own registered tree of heaven carries an official estimate of 120 to 165 years that the species' own growth pattern argues should be closer to 70 or 100. Rather than repeat that kind of guess, this page states the girth and leaves the age open. What is not in doubt is the tree itself, standing on one of Krakow's busiest historic streets, growing well before anyone thought to protect it.