Project based learning (PBL) provides opportunities for teachers and students to create learning spaces that are authentic and relevant. Much of this work is taking place in STEM contexts, with few studies exploring PBL integration in English language arts (ELA) classrooms. In this co-design project, we collaborated with 13 9th grade ELA teachers to design and enact PBL projects, exploring the ways in which they began to take up PBL core practices. Teachers appreciated the new content, saw increases in student engagement, and changed their instruction in positive ways. Problems of practice included integrating anchor texts into projects, teaching new literacies, and expanding assessment practices. Design decisions that respond to the complexity of PBL-ELA integration will be discussed.