I think it means -don't wait for a mate -go find one. If you walk through a field of broom you leave bent bushes behind you. The sisters were all trying to impress, vying for the affection of the man who showed up at their gate. He takes up with the youngest and the others are at risk of becoming old maids. He is suggesting- don't stick around here hoping and waiting. He had come seeking and found love and he is recommending others do he same. I believe "bend the broom" means to travel - and you'll beguile a lady soon. I am not very well researched in this but I have become very interested in learning and playing more of these old traditional songs. I would love to hear your opinion of my interpretation and any suggestions as to songs that I should know/learn. I am intrigued by the idea that the song originates in herbalist traditions, -tmayhew Martha's Vineyard, Massachusetts.