Would love to be on your list of 10 ... will you confirm its okay to send the stamps to you?

I do use a lot of mulch, but I've also been adding compost to these beds for 20 years or more. I do think it's pretty fertile because I get so many reseeders of other things, too- digitalis, larkspur, nigella, rudbeckia, Yvonne's salvia...the list goes on and on. And that's without mentioning the maple and birch trees. In my pre-organic days I used Preen and didn't have this problem. I'm seriously considering using it this spring after I hoe out the carpet of volunteers already growing now. It seems to be the only hope of getting them in control. I used corn gluten last summer with no apparent effect. I have applied thick leaf mulch most years in autumn but didn't do it this year. I also apply a good 3 in. of shredded wood mulch each spring. Doesn't help much. Karen

From what I understand this plant is not hardy in zone 4 if you are hoping for a perennial plant. The only verbena I have used is lemon verbena and never again I have now tried for 3 yrs to get rid of it to no avail,

Ha, I intentionally PULL the ones out of the more wild area here because I don't want them to get away and become invasive. In central PA (I'm also in 6A) V. bonariensis self-seeds very readily. The butterflies love it though so I continue to let it grow here, pulling all the extras out every year. If I don't, I think it would totally take over and crowd out all of my other garden plants except maybe the coneflowers. I don't have any other garden plants here that seed so vigorously, and I have a lot of different kinds of plants since I've been butterfly gardening since 2005. V. bonariensis is the very first plant that I saw my first Giant Swallowtail nectaring on. It's a great plant to have for them in the garden, but I control its spread and limit it to my garden and ONLY in the section that has been allocated for it.