There are verses, which I can't remember. Here's what I remember of the chorus.
A mother's loves a blessing, no matter where you roam
Love (?keep) her while she's living, you'll miss her when she's gone
Love her as in childhood, though she's feeble old and grey (charming eh??!!)
For you'll never miss your mother's love 'til she's buried beneath the clay.
Maybe this'll help someone else remember.