Pam Moore writes

I have never been able to keep the lemon verbena (aloysia?) over
winter.

It's not hardy in most of the UK. I think you can keep it against a
south facing wall in warmer parts. A shame, because to my nose it has a
far nicer lemon scent than the lemon balm.

I wonder if one can use lemon-scented pelargoniums in the same fashion?

Lemon balm (melissa?) does spread and seed itself about.

--
Kay