I've really enjoyed reading this post. I've had trouble with Verbena bonariensis too. I really wanted a row of it next to my greenhouse and then I could put zinnias and other flowers in front of it. This is in my "nectar" garden specifically for bees and butterflies. I didn't have much luck last year with the few seeds I put out that I collected off the one plant I had. This year I bought a packet of like 500 seeds from Geoseed. I put half out in Fall and half out early Spring figuring I'd get something up. It wasn't looking good and then it finally happened late Spring I got a nice row of about 25 plants. So over-seeding worked, I hope next year I get as many volunteers.
