Hearty plants for planters on concrete SoCal
I need to find hearty plants to put in 16" square planter boxes that are located on concrete at our school. There are 34 planter boxes in the courtyard. I think lantana will work, along with boxwood, heavenly bamboo, some types of rosemary, lavendar, and sage. What are your recommendations. We need some color and some variety, but don't want to replace these plants often. We are located in the Santa Clarita Valley and have hot summers and mild winters.