Learning to reason in the design process is enclosed in the process of learning to design. Hence, in this study, we explore teacher-student interactions with the aim of describing teachers' support strategies in relation to enacted reasoning in the design process in secondary school technology education in Sweden. The study deploys social cultural theory as a lens, with a focus on scaffolding means and intentions of the teacher. Relevant reasoning in the design process is theoretically framed as means-end reasoning and cause-effect reasoning. Empirical data was collected through three classroom observations with three different Swedish secondary school technology teachers, with subsequent interviews with the teachers using stimulated recall. During the observations the students were engage in different design processes. The data was analysed using thematic analysis, where themes as strategies were constructed for each reasoning type from patterns of meaning in teachers' scaffolding means and intentions. For each reasoning type, teachers employed strategies of decreasing control and increasing control. However, the enactment of these strategies differed in scaffolding intentions and means in relation to what reasoning was verbally enacted. Our findings indicate that teacher-student interactions within the design process in technology education classrooms hold significant meaning and value. This has implications for both teaching and learning in the field.