They grow as both annuals and perennials, it tolerates most soils– water when dry but when established Do not water overhead. Cut the verbena plants back at the end of the summer to encourage continued flowering. Fertilize the plants lightly with 16-4-8 fertilizer after you cut them back.
You can lift the plant about every 3 – 4 years and separate it and plant the separations into another location if you like in the spring – Dead head it to encourage new blooms
You can take cuttings and place in rooting powder then place in a glass of water they will root very well in a few weeks- as for the ones you have I see no need to bring into the green house – Ken

Thanks very much Ken. I still have pink trailing Verbena (and V. silver magic) in flower in tubs . . . perhaps I could try cuttings of them too. I've done Fuchsias in the past in water, but had no idea you could do that with Verbena. Useful info.

Very useful answer and question. Thank you both.

Trailing are very good for baskets - you only need one plant as they spread quickly - take cuttings as b4 - dip in hormone powder and place in glass of water - will show roots in a week or 2 - Good luck

OK, thanks Ken. I will try them. Funny . . . as I said, I used rooting powder on half of the Homestead Purple and not the other half, and there's absolutely no difference. Maybe I'll do that with the trailing ones . . .