The trees they do grow high is an originally Scottish ballad about an arranged child marriage, also known as The trees they grow so high, My bonny lad is young but he’s growing, Long a-Growing, Daily Growing, Still Growing, The Bonny Boy, and Lady Mary Ann. The song was very popular in the oral tradition in Scotland, England, Ireland, and the U.S.A. from the 18th to the 20th century. Questions about its true age (medieval?), the basis of its story (based on an actual marriage?) and its original author (Robert Burns?) have attracted conjectural claims. This article investigates the shifting narrative of the story over its lifetime and sifts the mere claims from the substantiated evidence.