I have grown Verbena bonariensis in the Piedmont and in the mountains of North Carolina for about 30 years, and invasive is one of the very last words I would use to describe it. Maybe it's the location, but I never have enough plants from natural reseeding each year, and so I began gathering some of the seeds growing extras in the greenhouse. I've always been fearful of not having any of this Verbena in my garden - that's how much I love it. I think a lot of folks feel the same way because it is the plant I sell the most of in my nursery. I strongly advise against taking someone else's word for something they consider invasive, unless it's Kudzu or Wisteria. This Verbena is an asset to any garden and if you are lucky to have too many in any given year (I should be so lucky), they are easy enough to pull up. If you are really worried, which you shouldn't be, you can always deadhead the spent flowers before seeds develop. This is one of the very best perennials out there.
