Meanwhile here is ' Can't you love whom you please' from c1790 printed in London and Edinburgh.

CAN'T YOU LOVE WHOM YOU PLEASE

When first in this country a stranger I came,
In fair Dublin city that place of great fame,
It was my misfortune a fair one to see,
It was the beginning of my misery.

I have oftentimes wondered how men could love maids
And a thousand times wondered how maids could love them
But they are deceitful, the truth I will tell,
I will never love a young man till he loves as well.

The man who says little I'm sure he is the best
And he that says nothing his heart is at rest;
He lives by experience his heart tells him so,
Every one to their own love, I know what I know.

Green grows the laurel, and so does the rue,
How sorry I was when I parted from you
The next happy meeting our joys may renew,
So I changed the green willow for the orange and blue.

Oh can't you love little, Oh can't you love long,
Oh can't you love a new one till the old one returns
Can't you say that you love him his mind for to ease,
And when his back's turned can't you love who you please.

As you can see, a jumble of stock phrases with little cohesion. They are probably commonplace stanzas and lines from other songs. The plant symbolism is quite common and easily interpreted, appearing in early versions of 'Sprig of Thyme' and 'Seeds of Love' among others.

The anomaly between the voices in the first 2 stanzas could point to an origin in a duet from a ballad opera.