Shall I hack my Verbena bonariensis?
Hi all, I'm just doing a pre winter tidy and wondered if you can give me some advice on pruning down my Verbena bonariensis. They've been in the ground since mid summer and have done well, and I want them to continue to do well next year. The flowers have died down and they're looking a bit sad. If I should cut them down, how low should I go? thanks guys!