Lemon Verbena Topiary
I have a lemon verbena herb that I am training into a nice little topiary tree. It's has a skinny little trunk with a nice round top (a work in progress!). My question is, is there anything I can do to help the trunk thicken up? I'd like it to look like an old tree with a nice thick trunk, but right now it looks like a little twig!! It's in a pot outside right now, but I will have to bring it in for the winter.
Also, any suggestions about overwintering it indoors. I know they like a lot of sun, and I"m afraid that I will not be able to provide adequate light. Any tips on letting it go dormant?