Assuming for just a moment that you're looking for a traditional song of that name, a few Revival performers seem to have recorded the only one I know of, though the limited information available online doesn't seem to include any mention of their source(s). The only traditional example listed in the Roud Folk Song Index (where it is number 9268) was recorded by Peter Kennedy from Billy Pennock of Goathland, Yorkshire, in 1953. More details can be seen at Peter's Folktrax site:

YORKSHIRE COUNTRY DANCES

The song was published on broadsides during the early 19th century. Examples can be seen at Bodleian Library Broadside Ballads:

The bonny hawthorn Printed between 1774 and 1825 by Angus of Newcastle. 2806 c.18(42)

The bonny hawthorn. A new song Printer and date unknown. Harding B 11(409) and Harding B 25(255)

The hawthorn Printed between 1816 and 1843 by T. Hoggett of Durham. Harding B 25(813)

Additionally, a search via Google (which you really ought to try) will get you a couple of copies of a transcription of a short set of lyrics, one with what appear to be suggested guitar chords. The transcription was made by a Czech (presumably by ear from a record), however, and isn't terribly coherent; neither is any source acknowledged so far as I can see, so it's likely to be of pretty limited use to anybody.