I gather from discussion with knowledgeable friends that Yates was 'inspired' to write Sally gardens from a verse in the 'Rambling Boys of Pleasure' (words and tune in the DT)........

It was down by Sally Gardens one evening late I took my way
'Twas there I spied this pretty little girl, and these words to me she did say.
She advised me to take love easy, as the leaves grown on the tree
But as I was young and foolish, with my darling could not agree

Sound familiar?

Catrin