"Dargason" is a humorous duet between tuba and piccolo. "Greensleeves" is there, plus a dance tune like the "Irish Washerwoman." All tunes used by Holst in the piece, however, are from Hampshire.
Someone should be able to recognize "I'll Love My Love," but Holst deliberately labeled it a song without words. I think it actually is an old tune that has received words, but I'm not able to identify it. Writers about the music of Holst always refer his melody to "an old English song," but never quote. Holst was a friend of and collected songs with Ralph Vaughan Williams.

Holst, Suite No. 2 in F

(www.gustavholst.info/compositions/listing.php?piece_id=5)

Lines from "All Around My Hat":

Some young men there are who are preciously deceitful,
A-coaxin' of the fair young maids they mean to lead astray,
As soon as they deceive them, so cruelly they leave them,
I'll love my love forever though she's far, far away.