This is bee balm.  I bought it last year and planted one plant.  I always buy one plant when I do not have any experience with it.  I let it grow for one full year before I decide whether or not to plant more.  Well I love bee balm.  It is beautiful and covered in bees.  Next to it is dill.  I planted that last year and it made it through the winter and is a giant this year.  I guess it also spreads easily by seed because I have little dill plants all over my veggie garden.  They are easy enough to pull out.  I think I planted it to sacrifice it to the caterpillars…