Verbena bonariensis -a bee favorite. This summer blooming beauty, also called purple vervain, reseeds every year, providing lots of new plants to move around the garden. It's an airy plant, about three or four feet tall and looks best when interplanted with more showy annuals like cosmos. It attracts all kinds of bees and butterflies, including the popular and threatened monarch. The plant can get a little scruffy by summer's end, so cut stalks for arrangements as a way of pruning.