I heard this song once, a long time ago, sung by John McCormack The only info I have on it is the following extract from somewhere or other:

The Fairy Tree
Music by Vincent O'Brien
Words by Temple Lane (real name M. Isabel Leslie)
This song was also written in 1930 – by Doctor Vincent O'Brien, who had been choirmaster to John McCormack when the singer was still an unknown student. O'Brien dedicated the song to the tenor's wife. It reads: 'To Lily. Countess McCormack. In kind remembrance'. This captivating piece contains traits of paganism and Christianity – a duality often found in the Celtic tradition.

Apparently the name Temple Lane was used as a pen-name because that's where Isabel Leslie lived - on Temple lane, near her father's rectory. The fairy tree is actually a solitary hawthorn tree.