With shifts in demographics leading to increasingly diverse student populations, and pressures from state educational accountability offices to streamline budgets and improve test scores, teachers at the secondary level are increasingly challenged to support English learners new to US schools. Teachers, often with minimal understanding of second language learning processes and ways of adapting content materials to meet the needs of language learners, become de facto language planners. Drawing on situated data from classroom activities and interviews with district personnel and teachers, this paper attempts to conceptually reconsider what language/culture and translanguaging/transcultural flows mean in secondary content area classrooms. By examining how teachers organize their practices and comparing these practices with state expectations in the area of content and language knowledge, this paper challenges current educational policy and planning efforts which seek to codify what constitutes language and what constitutes success in secondary school without taking students as cultural beings into account. The study concludes with suggestions for teacher education that support teachers developing as language planners.